FCGR3A and systemic lupus erythematosus: FCGR2A/FCGR3A has been reported to be a susceptibility gene for other autoimmune diseases, such as systemic lupus erythematosus [21, 22], rheumatoid arthritis [23], multiple sclerosis [24], type 1 diabetes [23] and ulcerative colitis [25, 26].