FCGR3A and cutaneous mastocytosis: FCGR3A (Fc fragment of IgG receptor IIIa) encodes the receptor for the Fc region of immunoglobulin G. FCGR3A interacts with FCGR1A in numerous pathophysiological processes and is substantially related with overall survival (OS) in CM, renal clear cell carcinoma, and other malignancies (49).