We observed the largest potential interaction effect size at the missense SNP rs1801232 in the CUBN gene in individuals of African ancestry, where the per-allele hazard ratio for T2D was 2.78 (95% CI = 1.92, 4.03, p = 5.5 x 10−8) among smokers and 1.01 (95% CI = 0.58, 1.77, p = 0.97) among non-smokers (pjoint = 1.3 x 10−7). The gene discussed is CUBN; the disease is type 2 diabetes mellitus.