– Signal-Regulatory Protein Gamma (SIRPG) is a member of the signal-regulatory protein (SIRP) family and also belongs to the immunoglobulin superfamily. SIRPG is detected in the liver, and at very low levels in the brain, heart, lung, pancreas, kidney, placenta, and skeletal muscle. SIRPG is an immunoglobulin-like cell surface receptor. On binding with CD47, SIRPG mediates cell-cell adhesion. Engagement on T-cells by CD47 on antigen-presenting cells results in enhanced antigen-specific T-cell proliferation and costimulates T-cell activation. SIRPG as receptor-type transmembrane glycoproteins is involved in the negative regulation of receptor tyrosine kinase-coupled signaling processes.