The function of Ensembl gene identifier ENSG00000131370 (SH3BP5, SH3 domain binding protein 5) is as follows. Functions as a guanine nucleotide exchange factor (GEF) with specificity for RAB11A and RAB25 (PubMed:26506309, PubMed:30217979). Inhibits the auto- and transphosphorylation activity of BTK. Plays a negative regulatory role in BTK-related cytoplasmic signaling in B- cells. May be involved in BCR-induced apoptotic cell death. {ECO:0000269|PubMed:10339589, ECO:0000269|PubMed:26506309, ECO:0000269|PubMed:30217979, ECO:0000269|PubMed:9571151}.