Signal Regulatory Proteins (SIRPs) comprise a family of several transmembrane glycoproteins (SIRPalpha, SIRPbeta, and SIRPgamma) that belong to immunoglobulin superfamily. SIRPgamma is also known as CD172g or SIRPbeta2 which is primarily expressed on T cells and a subpopulation of B cells. Like CD172a, the ligand of CD172g is CD47. But the binding affinity with CD172g is lower than CD172a. The biological functions of CD172g include regulation of T-cell transendothelial migration and induction of T cell apoptosis.