SIRPG, also known as signal-regulatory protein gamma isoform 1, is a member of a closely related family of three cell surface receptors implicated in modulating immune/inflammatory responses. It is expressed on T lymphocytes where it appears to be involved in the integrin-independent adhesion of lymphocytes to antigen-presenting cells. Adhesion of human T cells to antigen-presenting cells through it interaction costimulates T-cell proliferation. Recombinant human SIRPG, fused to hIgG-His-tag at C-terminus, was expressed in insect cell and purified by using conventional chromatography techniques.