TEC (Tyrosine-protein kinase Tec) is a member of the Tec family of non-receptor protein-tyrosine kinases containing a pleckstrin homology domain. Tec family kinases are involved in the intracellular signaling mechanisms of cytokine receptors, lymphocyte surface antigens, heterotrimeric G-protein coupled receptors and integrin molecules. They are also key players in the regulation of the immune functions. Tec kinase is an integral component of T cell signaling and has a distinct role in T cell activation. Tec may be associated with myelodysplastic syndrome.