In 2007, four genome-wide association studies (GWAS) conducted in African, Asian, North American, and European populations indicated that single-nucleotide polymorphism (SNPs) (there are at least 13 variants) exist in a previously uncharacterized gene: CDKAL1 was found to be a risk factor for type 2 diabetes (TD2) 26-32. The gene discussed is CDKAL1; the disease is type 2 diabetes mellitus.