Non-receptor tyrosine kinase indispensable for B lymphocyte development, differentiation and signaling. Binding of antigen to the B-cell antigen receptor (BCR) triggers signaling that ultimately leads to B-cell activation. After BCR engagement and activation at the plasma membrane, phosphorylates PLCG2 at several sites, igniting the downstream signaling pathway through calcium mobilization, followed by activation of the protein kinase C (PKC) family members. PLCG2 phosphorylation is performed in close cooperation with the adapter protein B-cell linker protein BLNK. Sulekha Verma, J. Biol. Chem., Feb 2001; 276: 4671 - 4676Yan M. Li, Cancer Res., Nov 2003; 63: 7630 - 7633Malti Nikrad, Mol. Cancer Ther., Mar 2005; 4: 443 - 449Feng Dong, Infect. Immun., Mar 2005; 73: 1861 - 1864Hiroo Ueno, Mol. Biol. Cell, Feb 2