Probable tyrosine protein-kinase, which has strong transforming capabilities on a variety of cell lines including NIH 3T3 fibroblasts and on athymic nude mice. When overexpressed, it can also induce tumor cell invasion as well as metastasis in distant organs. May act by activating both MAP kinase and phosphatidylinositol 3'-kinases (PI3K) pathways. ATP + L-tyrosyl-[protein] = ADP + H(+) + O-phospho-L-tyrosyl-[protein] Highly expressed in colon and small intestine. Weakly or not expressed in spleen, skeletal muscle, liver, kidney, heart and brain. Expressed in transformed kidney cell lines (COS-1 and HEK293T). Belongs to the protein kinase superfamily. Tyr protein kinase family.