Among EA smokers, these included rs4132670 (MAF = 0.30) and rs12243326 (MAF = 0.26), both in the well-described T2D-associated gene TCF7L2. Among AA smokers, rs1801232, a missense SNP in CUBN on chromosome 10 (MAF = 0.12), exhibited a significant main effect (S1 Fig). This evidence concerns the gene TCF7L2 and type 2 diabetes mellitus.