The results revealed that the BLK rs13277113 and rs2736340 polymorphisms increased the risk of autoimmune diseases in the total analysis (A vs G: OR = 1.33, 95% CI = 1.27–1.39, P < .01; T vs C: OR = 1.34, 95% CI = 1.27–1.41, P < .01), and rs4840568 was positively associated with systemic lupus erythematosus (SLE) (A vs G: OR = 1.32, 95% CI = 1.22–1.43, P = .01). The gene discussed is BLK; the disease is systemic lupus erythematosus.