As a whole, genetic and epigenetic studies of ABCG1 in T2D and IR univocally demonstrated that genetic modulation of ABCG1 was without effect on T2D and associated traits whereas methylation marks at the ABCG1 locus were consistently associated with T2D as well as the risk to develop T2D. The gene discussed is ABCG1; the disease is type 2 diabetes mellitus.