To our knowledge, this is the most comprehensive meta-analysis to assess the association of an FAS polymorphisms with the risk of autoimmune diseases, including SLE, RA, MS, AIH, LN, SSc, AA, pSS, HT, GBS, PBC, vitiligo, GD, T1D, IAA, JIA, and SPA. This evidence concerns the gene FAS and hematocrit.