{"entity":{"id":"stat5","kind":"target","name":"STAT5 (STAT5A, STAT5B)","aka":["STAT5A","STAT5B","signal transducer and activator of transcription 5"],"tldr":"STAT5 is the messenger that carries growth signals from FLT3, JAK2 and BCR::ABL1 into the nucleus and switches on survival genes in leukaemia cells. No drug hits STAT5 directly yet; the FLT3 and ABL inhibitors work by cutting off the signal above it.","summary":"STAT5A and STAT5B (both on chromosome 17q21.2) are transcription factors with a dual role in signal transduction and transcription: they bind GAS elements and activate prolactin-induced transcription; STAT5A mediates responses to KIT ligand, other growth factors, ERBB4 and possibly activated FGFRs, and STAT5B mediates responses to cytokines, hormones and growth factors including oncostatin M and positively regulates haematopoietic and erythroid differentiation (UniProt P42229, P51692). In OnCo, STAT5 is the downstream node that collapses when gilteritinib, midostaurin and quizartinib block FLT3-ITD and TKD signalling in AML and when ponatinib blocks BCR::ABL1 in Ph-positive leukaemia; the MPL record places it among the proteins docked by the activated thrombopoietin receptor.","asOf":"2026-09-22","links":[{"label":"HGNC HGNC:11366 (STAT5A)","url":"https://www.genenames.org/data/gene-symbol-report/#!/hgnc_id/HGNC:11366"},{"label":"HGNC HGNC:11367 (STAT5B)","url":"https://www.genenames.org/data/gene-symbol-report/#!/hgnc_id/HGNC:11367"},{"label":"UniProt P42229 (STAT5A)","url":"https://www.uniprot.org/uniprotkb/P42229/entry"},{"label":"UniProt P51692 (STAT5B)","url":"https://www.uniprot.org/uniprotkb/P51692/entry"},{"label":"NCBI Gene 6776 (STAT5A)","url":"https://www.ncbi.nlm.nih.gov/gene/6776"},{"label":"NCBI Gene 6777 (STAT5B)","url":"https://www.ncbi.nlm.nih.gov/gene/6777"}],"tags":["wave5-target"],"related":["gilteritinib","midostaurin","quizartinib","ponatinib","flt3","bcr-abl","jak2","mpl"],"cancers":["aml","aml-flt3","all-leukemia","cml-advanced-phase"],"sections":[],"technologies":[],"targets":[],"drugs":[],"companies":[],"institutions":[],"pathways":["jak-stat","aml-signalling","cml-signalling","bcr-abl1-signalling"],"terms":[],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":["Prevalence not recorded in this wave: HGNC and UniProt carry no positivity rates and no other source was consulted.","Two genes, so no single HGNC id on the record (the rule in scripts/enrich-target-ids.ts); both are cross-referenced in target-xrefs.ts."],"provenance":{"editedBy":"OnCo content wave 5 (HGNC REST, UniProt REST, corpus drug and pathway records)","editedOn":"2026-09-22"},"symbol":"STAT5A, STAT5B","biology":"The JAK-STAT pathway record lists STAT5 as the STAT of leukaemias, alongside STAT3 as the hub of IL-6-driven survival. Constitutive STAT5 signalling is the readout of FLT3, JAK2, MPL and BCR::ABL1 activity in the corpus mechanism steps, and no direct STAT5 inhibitor is recorded.","whereFound":["FLT3-mutant AML (downstream of FLT3-ITD/TKD)","Ph-positive CML and ALL (downstream of BCR::ABL1)","Myeloproliferative neoplasms (downstream of JAK2 and MPL)"],"targetClass":"transcription","prevalence":[]},"route":"/targets/stat5/","neighbours":{"drug":[{"id":"gilteritinib","kind":"drug","name":"Gilteritinib","route":"/drugs/gilteritinib/"},{"id":"midostaurin","kind":"drug","name":"Midostaurin","route":"/drugs/midostaurin/"},{"id":"ponatinib","kind":"drug","name":"Ponatinib","route":"/drugs/ponatinib/"},{"id":"quizartinib","kind":"drug","name":"Quizartinib","route":"/drugs/quizartinib/"}],"target":[{"id":"bcr-abl","kind":"target","name":"BCR::ABL1 (Philadelphia chromosome)","route":"/targets/bcr-abl/"},{"id":"flt3","kind":"target","name":"FLT3","route":"/targets/flt3/"},{"id":"jak2","kind":"target","name":"JAK2","route":"/targets/jak2/"},{"id":"mpl","kind":"target","name":"MPL (thrombopoietin receptor)","route":"/targets/mpl/"}],"cancer":[{"id":"all-leukemia","kind":"cancer","name":"Acute lymphoblastic leukaemia","route":"/cancers/all-leukemia/"},{"id":"aml","kind":"cancer","name":"Acute myeloid leukaemia","route":"/cancers/aml/"},{"id":"cml-advanced-phase","kind":"cancer","name":"Chronic myeloid leukaemia, accelerated and blast phase","route":"/cancers/cml-advanced-phase/"},{"id":"aml-flt3","kind":"cancer","name":"FLT3-mutated acute myeloid leukaemia","route":"/cancers/aml-flt3/"}],"pathway":[{"id":"aml-signalling","kind":"pathway","name":"Acute myeloid leukaemia (KEGG map)","route":"/pathways/aml-signalling/"},{"id":"bcr-abl1-signalling","kind":"pathway","name":"BCR::ABL1 (Philadelphia chromosome)","route":"/pathways/bcr-abl1-signalling/"},{"id":"cml-signalling","kind":"pathway","name":"Chronic myeloid leukaemia (KEGG map)","route":"/pathways/cml-signalling/"},{"id":"jak-stat","kind":"pathway","name":"JAK-STAT signalling","route":"/pathways/jak-stat/"}]}}