Enables several functions, including ATP binding activity; SH2 domain binding activity; and enzyme binding activity. Involved in several processes, including cell surface receptor signaling pathway; myeloid cell activation involved in immune response; and regulation of vesicle-mediated transport. Acts upstream of or within several processes, including positive regulation of leukocyte activation; positive regulation of macromolecule metabolic process; and protein phosphorylation. Located in early phagosome. Part of B cell receptor complex. Is expressed in liver. Human ortholog(s) of this gene implicated in primary immunodeficiency disease. Orthologous to human SYK (spleen associated tyrosine kinase). [provided by Alliance of Genome Resources, Apr 2022]