CYP4F2 and Hypertension: Only four case-control studies [8, 19, 25, 27] were enrolled to perform the male/female subgroup analysis for the association between CYP4AF2 rs1558139 and hypertension risk, while six studies [8, 19, 20, 23, 27, 32] were enrolled for CYP4F2 rs2108622.