CETP and type 2 diabetes mellitus: Low CETP haplotypes were found to be causally related to T2DM, with HDL as the mediator.13 Importantly, CETP polymorphisms tend to alter HDL-C levels by ≤5% whereas CETPi change HDL-C by up to 130%, which may explain some of the discordance between candidate-gene studies and clinical trials, though it must also be considered that CETPis are acting acutely whereas genetic polymorphisms act chronically.