Background：

Non-receptor tyrosine-protein kinase that plays a role in many biological processes including regulation of cell growth and survival， cell adhesion， integrin-mediated signaling， cytoskeletal remodeling， cell motility， immune response and axon guidance. Inactive FYN is phosphorylated on its C-terminal tail within the catalytic domain. Following activation by PKA， the protein subsequently associates with PTK2/FAK1， allowing PTK2/FAK1 phosphorylation， activation and targeting to focal adhesions. Involved in the regulation of cell adhesion and motility through phosphorylation of CTNNB1 (beta-catenin) and CTNND1 (delta-catenin). Regulates cytoskeletal remodeling by phosphorylating several proteins including the actin regulator WAS and the microtubule-associated proteins MAP2 and MAPT. Promotes cell survival by phosphorylating AGAP2/PIKE-A and preventing its apoptotic cleavage. Participates in signal transduction pathways that regulate the integrity of the glomerular slit diaphragm (an essential par