Spleen Tyrosine Kinase (SYK)

SYKis a member of the Syk family of tyrosine kinases. While Syk and Zap-70 are primarily expressed in hematopoietic tissues, there is expression of Syk in a variety of tissues. Within B and T cells respectively, Syk and Zap-70 transmit signals from the B-Cell receptor and T-Cell receptor. Syk plays a similar role in transmitting signals from a variety of cell surface receptors including CD74, Fc Receptor, and integrins. The role of Syk in epithelial malignancies is controversial. Several authors have suggested that abnormal Syk function facilitates transformation in Nasopharyngeal carcinoma and head and neck cancer while other authors have suggested a tumor suppressor role in breast and gastric cancer.