FCGR2A and type 1 diabetes mellitus: The studied variant rs1801274 in FCGR2A had been reported and it was associated with the susceptibility to multiple autoimmune diseases, including systemic lupus erythematosus (SLE), Kawasaki disease (KD), diabetes mellitus type 1 (T1D), autoimmune thyroid disease (ATD), ulcerative colitis (UC), Crohn's disease (CD), rheumatoid arthritis (RA) [5–11], etc. However, the inadequate statistical data, ethnic differences or publication bias resulting in the controversial and inconclusive in different case-control studies.