Approximately 25 established T2DM loci (ADAMTS9, ALX4, BCL11A, CDKAL1, CDKN2A/B, COL8A1, DUSP9, FTO, GCK, GNPDA2, HMG20A, HNF1A, HNF1B, HNF4A, IGF2BP2, JAZF1, KCNJ11, KCNQ1, MC4R, PPARγ, SLC30A8, TCF7L2, TFAP2B, TP53INP1, and WFS1) and few established obesity loci (ADIPOQ, FTO, RFX7, and USP37) are observed to replicate in the Arab population (Table 1). The gene discussed is TCF7L2; the disease is type 2 diabetes mellitus.