Non-receptor tyrosine kinase that plays central but diverse modulatory roles in various signaling processes involved in the regulation of actin reorganization, cell migration, cell proliferation and survival, cell adhesion, and apoptosis. Participates in signal transduction stimulated by growth factor receptors, cytokine receptors, G-protein coupled receptors, antigen receptors and integrins. Induces tyrosine phosphorylation of BCAR1 in response to integrin regulation. Activation of BMX by integrins is mediated by PTK2/FAK1, a key mediator of integrin signaling events leading to the regulation of actin cytoskeleton and cell motility. Plays a critical role in TNF-induced angiogenesis, and implicated in the signaling of TEK and FLT1 receptors, 2 important receptor families essential for angiogenesis. Required for the phosphorylation and activation of STAT3, a transcription factor involved in cell differentiation. Also involved in interleukin-6 (IL6) induced differentiation. Also plays a role in programming adaptive cytoprotection against extracellular stress in different cell systems, salivary epithelial cells, brain endothelial cells, and dermal fibroblasts. May be involved in regulation of endocytosis through its interaction with an endosomal protein RUFY1. May also play a role in the growth and differentiation of hematopoietic cells; as well as in signal transduction in endocardial and arterial endothelial cells. ATP + L-tyrosyl-[protein] = ADP + H(+) + O-phospho-L-tyrosyl-[protein] Binds 1 zinc ion per subunit. TEK and vascular endothelial growth factor receptor 1 (FLT1) stimulate BMX tyrosine kinase activity. Activated by integrins through the mediation of PTK2/FAK1 (By similarity). Activated by TNF through the mediation of TNFRSF1B (By similarity). Interacts with BCAR1, CAV1, MYD88, PTK2/FAK1, RUFY1, RUFY2, STAT3, TIRAP and TNFRSF1B. Localizes to the edges of spreading cells when complexed with BCAR1. Specifically expressed in the endocardium of the developing heart as well as in the endocardium of the left ventricle and in the endothelium of large arteries in adult mice. SH2 domain mediates interaction with RUFY1. Phosphorylated in response to protein I/II and to LPS. Phosphorylation at Tyr-542 by SRC and by autocatalysis leads to activation and is required for STAT3 phosphorylation by BMX. Belongs to the protein kinase superfamily. Tyr protein kinase family. TEC subfamily.