SLAMF1 is a member of the immunoglobulin gene superfamily and is involved in T-cell stimulation. The SLAMF1 protein is constitutively expressed on peripheral blood memory T cells， T-cell clones， immature thymocytes， and a fraction of B cells， and is swiftly induced on naive T cells after activation. There are probably 2 modes of SLAM signaling: one in which the inhibitor SH2D1A serves as a negative regulator and another in which protein-tyrosine phosphatase 2C （PTPN11）-dependent signal transduction functions.
