The function of VSIG4 (V-set and immunoglobulin domain containing 4, ENSG00000155659) is as follows. Phagocytic receptor, strong negative regulator of T-cell proliferation and IL2 production. Potent inhibitor of the alternative complement pathway convertases. {ECO:0000269|PubMed:17016562, ECO:0000269|PubMed:17051150}.