Signaling lymphocytic activation molecule (SLAM,also known as SLAMF1 or CD150) is a 70-kDa transmembrane glycoprotein that belongs to the immunoglobulin gene superfamily. SLAM is constitutively expressed on peripheral blood memory T-cells,T-cell clones,immature thymocytes and a proportion of B-cells,and is rapidly induced on naive T-cells after activation. SLAM is involved in T cell stimulation and cytokine production,and may play an important role in the regulation of immune responses to pathogens.