Tyrosine-protein kinase that acts downstream of cell surface receptors and plays a role in the regulation of the actin cytoskeleton; microtubule assembly; cell attachment and cell spreading. Plays a role in FCER1 (high affinity immunoglobulin epsilon receptor)-mediated signaling in mast cells. Acts down- stream of the activated FCER1 receptor and the mast/stem cell growth factor receptor KIT. Plays a role in the regulation of mast cell degranulation. Plays a role in the regulation of cell differentiation and promotes neurite outgrowth in response to NGF signaling. Plays a role in cell scattering and cell migration in response to HGF-induced activation of EZR. Phosphorylates BCR and down-regulates BCR kinase activity. Phosphorylates HCLS1/HS1; PECAM1; STAT3 and TRIM28. {ECO:0000269|PubMed:11509660; ECO:0000269|PubMed:15302586; ECO:0000269|PubMed:15485904; ECO:0000269|PubMed:16455651; ECO:0000269|PubMed:17595334; ECO:0000269|PubMed:18046454; ECO:0000269|PubMed:19001085; ECO:0000269|PubMed:19051325; ECO:0000269|PubMed:20111072; ECO:0000269|PubMed:2656706; ECO:0000269|PubMed:8955135}.