SLC9A4

gene
On this page

Also known as NHE4

Summary

SLC9A4 (solute carrier family 9 member A4, HGNC:11077) is a protein-coding gene on chromosome 2q12.1, encoding Sodium/hydrogen exchanger 4 (Q6AI14). Electroneutral antiporter that exchanges sodium for protons or ammonium ions at the basolateral membrane of epithelia to regulate cell volume and intracellular pH upon hypertonic conditions.

Predicted to enable potassium:proton antiporter activity and sodium:proton antiporter activity. Predicted to be involved in monoatomic cation transmembrane transport; regulation of intracellular pH; and transepithelial ammonium transport. Predicted to act upstream of or within gastric acid secretion and glandular epithelial cell development. Predicted to be located in basolateral plasma membrane. Predicted to be active in plasma membrane.

Source: NCBI Gene 389015 — RefSeq curated summary.

At a glance

  • GWAS associations: 21
  • Clinical variants (ClinVar): 159 total
  • MANE Select transcript: NM_001011552

Identifiers

Gene identifiers

FieldValue
HGNC IDHGNC:11077
Approved symbolSLC9A4
Namesolute carrier family 9 member A4
Location2q12.1
Locus typegene with protein product
StatusApproved
AliasesNHE4
Ensembl geneENSG00000180251
Ensembl biotypeprotein_coding
OMIM600531
Entrez389015

Gene structure

Transcript identifiers

Ensembl transcripts: 2 — 1 protein_coding, 1 retained_intron

ENST00000295269, ENST00000492154

RefSeq mRNA: 1 — MANE Select: NM_001011552 NM_001011552

CCDS: CCDS33264

Canonical transcript exons

ENST00000295269 — 12 exons

ExonStartEnd
ENSE00000999646102519859102519955
ENSE00000999647102514090102514251
ENSE00001163913102512203102512273
ENSE00001237904102525024102525155
ENSE00001471641102532330102533972
ENSE00001471643102526259102526346
ENSE00001471644102508847102508933
ENSE00001471646102508079102508281
ENSE00001471647102505254102505471
ENSE00001471648102503448102503707
ENSE00001471649102478839102479302
ENSE00001471650102473226102474015

Expression profiles

Bgee: expression breadth broad, 67 present calls, max score 83.87.

FANTOM5 (CAGE): breadth tissue_specific, TPM avg 0.1582 / max 82.5784, expressed in 66 samples.

FANTOM5 promoters (6 alternative TSS)

Promoter IDTPM avgSamples expressed
217520.042821
217510.034714
217480.02355
217500.02247
217490.02106
217530.01385

Top tissues by expression

125 total, by Bgee expression score (0-100, higher = more expressed):

TissueAnatomy IDExpression scoreQuality
male germ line stem cell (sensu Vertebrata) in testisCL:0000089 ∩ UBERON:000047383.87gold quality
stomachUBERON:000094579.33gold quality
body of stomachUBERON:000116178.30gold quality
adult mammalian kidneyUBERON:000008275.10gold quality
fundus of stomachUBERON:000116072.84gold quality
kidneyUBERON:000211370.85gold quality
metanephros cortexUBERON:001053369.12gold quality
gall bladderUBERON:000211067.36gold quality
lower esophagus mucosaUBERON:003583465.76gold quality
duodenumUBERON:000211464.82gold quality
mucosa of stomachUBERON:000119960.90gold quality
cortex of kidneyUBERON:000122558.14gold quality
olfactory segment of nasal mucosaUBERON:000538657.04gold quality
tonsilUBERON:000237253.97gold quality
esophagus mucosaUBERON:000246953.38gold quality
endometriumUBERON:000129552.82gold quality
saliva-secreting glandUBERON:000104451.08gold quality
urinary bladderUBERON:000125549.55gold quality
minor salivary glandUBERON:000183049.49gold quality
ganglionic eminenceUBERON:000402348.01silver quality
rectumUBERON:000105246.54gold quality
bone marrowUBERON:000237145.27gold quality
skin of legUBERON:000151144.80gold quality
bone marrow cellCL:000209244.20gold quality
zone of skinUBERON:000001444.15gold quality
skin of abdomenUBERON:000141642.89gold quality
colonic epitheliumUBERON:000039741.16gold quality
esophagusUBERON:000104340.86gold quality
bloodUBERON:000017840.51gold quality
prefrontal cortexUBERON:000045140.08silver quality

Single-cell (SCXA)

Detected in 2 experiment(s), a significant marker in 1.

ExperimentMarker?Max mean expression
E-ANND-3yes4.23
E-MTAB-6386no14.88

Regulation

Is transcription factor: no

Literature-anchored findings (GeneRIF, showing 4)

  • T84 human colon cells contain three isoforms of the Na+/H+ exchanger, NHE1, NHE2, and NHE4, but not the Cl-dependent NHE (PMID:17943310)
  • Data demonstrate functional NHE4 activity in the rat and human colon and suggest that this exchanger is capable of modulating intracellular pH over a wide pH spectrum and may play an important role in maintaining cellular pH homeostasis. (PMID:22049213)
  • Integrating disease and drug-related phenotypes for improved identification of pharmacogenomic variants. (PMID:33769074)
  • Rare variant analysis in eczema identifies exonic variants in DUSP1, NOTCH4 and SLC9A4. (PMID:34785669)

Cross-species orthologs

8 orthologs

OrganismSymbolGene ID
mus_musculusSlc9a4ENSMUSG00000026065
rattus_norvegicusSlc9a4ENSRNOG00000015306
drosophila_melanogasterNhe3FBGN0028703
drosophila_melanogasterNhe2FBGN0040297
caenorhabditis_elegansWBGENE00003730
caenorhabditis_elegansWBGENE00003732
caenorhabditis_elegansWBGENE00003733
caenorhabditis_elegansWBGENE00003734

Paralogs (10): SLC9A7 (ENSG00000065923), SLC9A3 (ENSG00000066230), SLC9A1 (ENSG00000090020), SLC9A2 (ENSG00000115616), SLC9A5 (ENSG00000135740), SLC9C2 (ENSG00000162753), SLC9C1 (ENSG00000172139), SLC9A9 (ENSG00000181804), SLC9A8 (ENSG00000197818), SLC9A6 (ENSG00000198689)

Protein

Protein identifiers

Sodium/hydrogen exchanger 4Q6AI14 (reviewed: Q6AI14)

Alternative names: Na(+)/H(+) exchanger 4, Solute carrier family 9 member 4

All UniProt accessions (1): Q6AI14

UniProt curated annotations — full annotation on UniProt →

Function. Electroneutral antiporter that exchanges sodium for protons or ammonium ions at the basolateral membrane of epithelia to regulate cell volume and intracellular pH upon hypertonic conditions. As part of transcellular ammonia transport in renal tubules, mediates basolateral ammonium extrusion in the medullary thick ascending limb, regulating the corticopapillary ammonium gradient and overall renal acid excretion. Mediates sodium:proton exchange in gastric parietal cells secondary to cAMP-dependent acid secretion and hyperosmolarity. Possibly coupled to chloride:bicarbonate antiporter, enables loading of parietal cells with sodium and chloride ions to maintain cell volume and normal gastric acid secretion. Functions as a sodium sensor in neurons of organum vasculosum of the lamina terminalis where it regulates water intake in response to increased sodium concentration in body fluids.

Subunit / interactions. Homodimer; each protomer has one site for sodium and one site for proton binding. Interacts with CHP1 and CHP2.

Subcellular location. Basolateral cell membrane. Apical cell membrane. Zymogen granule membrane.

Post-translational modifications. May be phosphorylated.

Similarity. Belongs to the monovalent cation:proton antiporter 1 (CPA1) transporter (TC 2.A.36) family.

RefSeq proteins (1): NP_001011552* (*=MANE)

Domains & families (InterPro)

IDNameType
IPR001953NHE-2/4Family
IPR004709NaH_exchangerFamily
IPR006153Cation/H_exchanger_TMDomain
IPR018422Cation/H_exchanger_CPA1Family
IPR032103NHE_CaM-bdDomain

Pfam: PF00999, PF16644

Catalyzed reactions (Rhea), 2 shown:

  • Na(+)(in) + H(+)(out) = Na(+)(out) + H(+)(in) (RHEA:29419)
  • Na(+)(out) + NH4(+)(in) = Na(+)(in) + NH4(+)(out) (RHEA:76431)

UniProt features (36 total): topological domain 14, transmembrane region 10, intramembrane region 3, region of interest 2, sequence variant 2, sequence conflict 2, chain 1, compositionally biased region 1, glycosylation site 1

Structure

Experimental structures (PDB)

0 structures.

Predicted structure (AlphaFold)

ModelpLDDTFraction very-high
AF-Q6AI14-F166.730.26

Functional residue map

Curated UniProt residues grouped by drug-discovery relevance — catalytic, ligand-binding, modification, and mutation-validated positions. Source: UniProtKB sequence features.

Glycosylation sites (1): 342

Function

Pathways and Gene Ontology

Reactome pathways

4 pathways

IDPathway
R-HSA-425986Sodium/Proton exchangers
R-HSA-382551Transport of small molecules
R-HSA-425393
R-HSA-425407SLC-mediated transmembrane transport

MSigDB gene sets: 91 (showing top): GOBP_POTASSIUM_ION_TRANSPORT, GOBP_DIGESTION, GOBP_EPITHELIUM_DEVELOPMENT, GOBP_ACID_SECRETION, GOBP_EPITHELIAL_CELL_DEVELOPMENT, GOCC_SECRETORY_GRANULE, GOBP_SODIUM_ION_TRANSMEMBRANE_TRANSPORT, chr2q12, GOBP_MONOATOMIC_CATION_TRANSPORT, GOBP_TRANSEPITHELIAL_TRANSPORT, GOBP_SECRETION, GOBP_DIGESTIVE_SYSTEM_PROCESS, GOMF_PROTON_TRANSMEMBRANE_TRANSPORTER_ACTIVITY, GOBP_REGULATION_OF_PH, GOCC_APICAL_PLASMA_MEMBRANE

GO Biological Process (12): gastric acid secretion (GO:0001696), glandular epithelial cell development (GO:0002068), monoatomic ion transport (GO:0006811), regulation of intracellular pH (GO:0051453), transepithelial ammonium transport (GO:0070634), potassium ion transmembrane transport (GO:0071805), sodium ion import across plasma membrane (GO:0098719), monoatomic cation transport (GO:0006812), sodium ion transport (GO:0006814), regulation of pH (GO:0006885), transmembrane transport (GO:0055085), proton transmembrane transport (GO:1902600)

GO Molecular Function (3): sodium:proton antiporter activity (GO:0015385), potassium:proton antiporter activity (GO:0015386), antiporter activity (GO:0015297)

GO Cellular Component (6): plasma membrane (GO:0005886), basolateral plasma membrane (GO:0016323), apical plasma membrane (GO:0016324), zymogen granule membrane (GO:0042589), membrane (GO:0016020), cytoplasmic vesicle (GO:0031410)

Reactome top-level categories

Rollup of top-2 pathways:

CategoryPathways
Metal ion SLC transporters1
Transport of small molecules1

GO top-level categories

Rollup of top GO terms by namespace:

CategoryTerms
transport2
monoatomic cation transmembrane transport2
metal cation:proton antiporter activity2
plasma membrane region2
digestive system process1
acid secretion1
columnar/cuboidal epithelial cell development1
glandular epithelial cell differentiation1
regulation of pH1
intracellular monoatomic cation homeostasis1
regulation of biological quality1
transepithelial transport1
nitrogen compound transport1
potassium ion transport1
sodium ion transmembrane transport1
inorganic cation import across plasma membrane1
monoatomic ion transport1
metal ion transport1
monoatomic cation homeostasis1
biological regulation1
cellular process1
sodium ion transmembrane transporter activity1
solute:potassium antiporter activity1
secondary active transmembrane transporter activity1
membrane1
cell periphery1
basal plasma membrane1
apical part of cell1
secretory granule membrane1
zymogen granule1
cellular anatomical structure1
cytoplasm1
intracellular vesicle1

Protein interactions and networks

STRING

738 interactions, top by confidence (×1000):

Protein AProtein BPartner UniProtScore
SLC9A4SLC9B2Q86UD5585
SLC9A4IL18R1Q13478574
SLC9A4SLC12A1Q13621546
SLC9A4SLC26A6Q9BXS9532
SLC9A4IL1RL1Q01638520
SLC9A4RHCGQ9UBD6514
SLC9A4SLC4A7Q9Y6M7513
SLC9A4SLC9B1Q4ZJI4496
SLC9A4ENTR1Q96C92490
SLC9A4RHBGQ9H310472
SLC9A4NKX2-3Q8TAU0468
SLC9A4CALM1P02593465
SLC9A4NHERF1O14745453
SLC9A4SLC4A4Q9Y6R1446
SLC9A4SLC4A5Q9BY07440

IntAct

4 interactions, top by confidence:

ABTypeScore
SLC9A4RNF181psi-mi:“MI:0915”(physical association)0.400
IL37SLC9A4psi-mi:“MI:0915”(physical association)0.400
SLC9A4TMEM131Lpsi-mi:“MI:0914”(association)0.350

BioGRID (66): SLC9A4 (Reconstituted Complex), SLC9A4 (Reconstituted Complex), RNF181 (Affinity Capture-MS), SLC9A4 (Affinity Capture-MS), ABHD15 (Affinity Capture-MS), ADCY3 (Affinity Capture-MS), AMFR (Affinity Capture-MS), ARL6IP6 (Affinity Capture-MS), ATF6 (Affinity Capture-MS), B3GALNT2 (Affinity Capture-MS), BAG2 (Affinity Capture-MS), BAG5 (Affinity Capture-MS), CHP1 (Affinity Capture-MS), CNNM1 (Affinity Capture-MS), DNAJB1 (Affinity Capture-MS)

ESM2 similar proteins: A1L3P4, A4IHB9, D3ZJ86, D4A7H1, F7B113, O00341, O16452, O54701, P19634, P23791, P26431, P26432, P26434, P31596, P35449, P43004, P43006, P48761, P48762, P48763, P48764, P50482, Q01345, Q28036, Q3ZAS0, Q4R335, Q56XP4, Q61165, Q68KI4, Q6AI14, Q6DFC0, Q84WG1, Q8BLV3, Q8BUE1, Q8BUN9, Q8BYR8, Q8BZ00, Q8IVB4, Q8JZR4, Q8RWU6

Diamond homologs: A1L3P4, B2RXE2, D3ZJ86, D4A7H1, F7B113, G3X939, M5A7P9, O13726, P19634, P23791, P26431, P26432, P26433, P26434, P48761, P48762, P48763, P48764, Q01345, Q04121, Q14940, Q28362, Q3ZAS0, Q4L208, Q4R8V4, Q552S0, Q56XP4, Q58916, Q5ZJ75, Q61165, Q68KI4, Q6AI14, Q84WG1, Q8BLV3, Q8BUE1, Q8BZ00, Q8IVB4, Q8R4D1, Q8RWU6, Q8S396

SIGNOR signaling

2 interactions.

AEffectBMechanism
SLC9A4“down-regulates quantity”hydronrelocalization
SLC9A4“up-regulates quantity”sodium(1+)relocalization

Disease & clinical

Clinical variants and AI predictions

ClinVar

159 variants total. Per-class counts are floors (≥ shown; pagination cap):

ClassificationCount (floor)
Pathogenic0
Likely pathogenic0
Uncertain significance136
Likely benign7
Benign1

Top pathogenic / likely-pathogenic (0)

SpliceAI

2222 predictions. Top by Δscore:

VariantEffectΔscore
2:102479231:G:GTdonor_gain1.0000
2:102505251:TAGA:Tacceptor_loss1.0000
2:102505252:A:AGacceptor_gain1.0000
2:102505253:G:GCacceptor_gain1.0000
2:102505253:GA:Gacceptor_gain1.0000
2:102505253:GAA:Gacceptor_gain1.0000
2:102505253:GAATC:Gacceptor_gain1.0000
2:102505462:A:Tdonor_gain1.0000
2:102505469:TCA:Tdonor_gain1.0000
2:102505472:G:GGdonor_gain1.0000
2:102505483:C:Tdonor_gain1.0000
2:102508932:GT:Gdonor_gain1.0000
2:102508934:G:GGdonor_gain1.0000
2:102512274:G:GGdonor_gain1.0000
2:102514247:CATCA:Cdonor_gain1.0000
2:102514249:TCA:Tdonor_gain1.0000
2:102514250:CA:Cdonor_gain1.0000
2:102514252:G:GGdonor_gain1.0000
2:102525113:G:GTdonor_gain1.0000
2:102525126:A:Tdonor_gain1.0000
2:102526244:A:AGacceptor_gain1.0000
2:102526244:ACTT:Aacceptor_gain1.0000
2:102526343:TCAG:Tdonor_loss1.0000
2:102526344:CAGG:Cdonor_loss1.0000
2:102526345:AGGT:Adonor_loss1.0000
2:102526346:GGTAA:Gdonor_loss1.0000
2:102526348:T:Gdonor_loss1.0000
2:102476062:A:Gdonor_gain0.9900
2:102479300:GTG:Gdonor_gain0.9900
2:102503442:GCCTA:Gacceptor_loss0.9900

AlphaMissense

5266 scored. Top likely-pathogenic:

VariantProtein changeam_pathogenicity
2:102503581:G:AG285E0.999
2:102503655:A:CS310R0.999
2:102503657:C:AS310R0.999
2:102503657:C:GS310R0.999
2:102478983:T:CL134P0.998
2:102503593:C:AA289E0.998
2:102503635:C:AP303Q0.998
2:102503635:C:GP303R0.998
2:102503644:T:AV306D0.998
2:102505299:C:AN342K0.998
2:102505299:C:GN342K0.998
2:102505357:A:CS362R0.998
2:102505359:C:AS362R0.998
2:102505359:C:GS362R0.998
2:102473985:T:AW76R0.997
2:102473985:T:CW76R0.997
2:102478989:C:GP136R0.997
2:102503569:G:AG281D0.997
2:102503580:G:AG285R0.997
2:102503580:G:CG285R0.997
2:102479001:T:CL140P0.996
2:102503568:G:CG281R0.996
2:102505384:G:CG371R0.996
2:102478989:C:AP136Q0.995
2:102503556:G:AG277R0.995
2:102503556:G:CG277R0.995
2:102503605:G:CR293P0.995
2:102503676:G:CA317P0.995
2:102503677:C:AA317D0.995
2:102505268:C:AA332E0.995

dbSNP variants (sampled 300 via entrez): RS1000046180 (2:102491307 T>A), RS1000102975 (2:102512688 G>A,T), RS1000175109 (2:102512587 C>A,T), RS1000216993 (2:102474754 C>A,T), RS1000243556 (2:102494464 T>A,C), RS1000318996 (2:102472181 T>C), RS1000327172 (2:102509924 C>G,T), RS1000462262 (2:102485274 C>G), RS1000518225 (2:102492039 T>C), RS1000525090 (2:102477443 A>C), RS1000537601 (2:102471957 C>T), RS1000652644 (2:102474413 G>A), RS1000668041 (2:102490040 T>C), RS1000677731 (2:102482659 A>T), RS1000684072 (2:102529749 C>G)

Disease associations

OMIM: gene MIM:600531 | disease phenotypes: MIM:207500, MIM:301800

GenCC curated gene-disease

Mondo (1): imperforate anus (MONDO:0001046)

Orphanet (1): Non-syndromic anorectal malformation (Orphanet:557)

HPO phenotypes

0 total (0 of 0 shown, HPO-id order):

GWAS associations

21 associations (top):

StudyTraitp-value
GCST000157_6Celiac disease4.000000e-09
GCST001134_14White blood cell types7.000000e-06
GCST002166_8Serum protein levels (sST2)3.000000e-33
GCST003542_105Night sleep phenotypes9.000000e-06
GCST004131_93Inflammatory bowel disease5.000000e-11
GCST004132_63Crohn’s disease6.000000e-11
GCST004627_78Lymphocyte count6.000000e-16
GCST005851_3Delirium1.000000e-08
GCST007563_2Allergic disease (asthma, hay fever or eczema)4.000000e-24
GCST007564_34Asthma or allergic disease (pleiotropy)2.000000e-27
GCST008058_275Estimated glomerular filtration rate1.000000e-07
GCST008059_210Estimated glomerular filtration rate2.000000e-08
GCST008097_17Bisphosphonate-associated atypical femoral fracture1.000000e-06
GCST008489_8Celiac disease3.000000e-08
GCST008916_108Asthma1.000000e-22
GCST008916_29Asthma2.000000e-60
GCST009874_7Celiac disease2.000000e-16
GCST010090_2Atopic dermatitis6.000000e-11
GCST90000025_759Appendicular lean mass2.000000e-16
GCST90002379_24Basophil count5.000000e-12
GCST90002391_137Mean corpuscular hemoglobin concentration5.000000e-13

EFO canonical traits (7, from GWAS)

EFO IDTrait name
EFO:0004842eosinophil count
EFO:0004587lymphocyte count
EFO:0009958response to bisphosphonate
EFO:0009960atypical femoral fracture
EFO:0004980appendicular lean mass
EFO:0005090basophil count
EFO:0004528mean corpuscular hemoglobin concentration

MeSH disease descriptors (1)

DescriptorNameTree numbers
D001006Anus, ImperforateC06.198.050; C16.131.314.094

Drugs & pharmacology

Drug and pharmacology data

Is drug target: no

PharmGKB: 1 entry (VIP=true, CPIC=false)

GtoPdb / IUPHAR curated pharmacology

(IUPHAR/BPS Guide to Pharmacology — expert-curated)

Target class: transporter — SLC9 family of sodium/hydrogen exchangers

CTD chemical–gene interactions

14 total (human), top 14 by PubMed support.

ChemicalActions (top 5)PubMed papers
sodium arseniteincreases expression1
aflatoxin B2increases methylation1
S-(1,2-dichlorovinyl)cysteineaffects response to substance, increases expression, affects cotreatment1
CGP 52608affects binding, increases reaction1
3-iodothyronamineaffects uptake1
abrinedecreases expression1
NSC668394increases expression1
Benzo(a)pyreneincreases methylation1
Caffeineincreases phosphorylation1
Estradioldecreases expression1
Lipopolysaccharidesaffects response to substance, increases expression, affects cotreatment1
Protonsaffects transport1
Tobacco Smoke Pollutionaffects expression1
Aflatoxin B1decreases methylation1

Clinical trials (associated diseases)

18 trials via MONDO — disease-level, not drug-specific.

TrialPhaseStatusTitle
NCT04904081PHASE3UNKNOWNFeasibility of Use of Indocyanine Green in Pediatric Colorectal Surgery
NCT00883571Not specifiedCOMPLETEDComparative Study of the House Advancement Flap, Rhomboid Flap, and Y-V Anoplasty
NCT04106947Not specifiedUNKNOWNTransition of Care for Patients With Hirschsprung Disease and Anorectal Malformations
NCT04710433Not specifiedCOMPLETEDNon-invasive Sacral Nerve Stimulation in Children and Adolescents With Chronic Constipation
NCT04713085Not specifiedCOMPLETEDSacral Neuromodulation in Children and Adolescents
NCT04901819Not specifiedCOMPLETEDLongterm Outcomes of Individuals With Anorectal Malformations
NCT05045560Not specifiedCOMPLETEDStudy of Antenatal and Postnatal Data of Anorectal Malformations Diagnosed at Montpellier University Hospital Over a 10-year Period (2010-2020)
NCT05293353Not specifiedUNKNOWNNeokare Safety and Tolerability Assessment in Neonates With GI Problems
NCT05450991Not specifiedRECRUITINGLong-term Qualitative and Quantitative Outcomes of Children With Hirschsprung’s Disease and Anorectal Malformations
NCT05621629Not specifiedCOMPLETEDManagement of FI After Surgery of ARM
NCT05749406Not specifiedUNKNOWNParental Attitudes to Neoanus Dilatations Post-reconstruction in Anorectal Malformations
NCT06065995Not specifiedTERMINATEDStoMakker Mobile Application
NCT06234020Not specifiedCOMPLETEDFrequency of Vertebrospinal Anomalies in Patients Presenting With Anorectal Malformations
NCT06860906Not specifiedCOMPLETEDV-Y Flap for Anal Stenosis
NCT07029984Not specifiedRECRUITINGBaylor Continence Scale Validity in Anorectal Malformation
NCT07099339Not specifiedCOMPLETEDEffect of Pudendal Nerve Electrical Stimulation on Fecal Incontinence in Children With Repaired Anorectal Malformation
NCT07366476Not specifiedNOT_YET_RECRUITINGEffectiveness of Electrical Stimulation and Biofeedback on Fecal Incontinence in Children With Repaired Anorectal Malformation
NCT07438691Not specifiedRECRUITINGOutcomes in ARMs: Comparison Between Surgical Techniques in Patients With Perineal or Vestibular Fistula - a Multicenter Italian Study