This gene was identified by its ability to suppress the tumorigenicity of Hela cells in nude mice. The protein encoded by this gene contains a C-terminal region that shares similarity with the Rab 3 family of small GTP binding proteins. This protein preferentially binds to the SH3 domain of c-Abl kinase, and acts as a regulator of MAPK1/ERK2 kinase, which may contribute to its ability to reduce the tumorigenic phenotype in cells. Three alternatively spliced transcript variants of this gene encoding distinct isoforms are identified.ST5 (Suppression Of Tumorigenicity 5) is a Protein Coding gene. Diseases associated with ST5 include Miller Fisher Syndrome and Opportunistic Mycosis. Among its related pathways are Vesicle-mediated transport and RAB GEFs exchange GTP for GDP on RABs. GO annotations related to this gene include Rab guanyl-nucleotide exchange factor activity. An important paralog of this gene is DENND2A.