Further Mendelian randomization study found that, PCSK9 variants and 3-hydroxy-3-methylglutaryl–coenzyme A reductase (HMGCR) variants had roughly the same effect on the risk of MACEs and T2DM per unit decrease in LDL-C level, whose scores had additive effects. This evidence concerns the gene PCSK9 and type 2 diabetes mellitus.