Kajiwara and his fellows, first identified five non-synonymous SNPs (V10L, G64D, A310V, D328A and N474S) in MATE-1 that exhibited a significant decrease in transport activity.19 We decided to investigate the effect of one of these unexplored variants (rs 77630697, MATE-1 G64D) in the SLC47A1 gene on metformin therapy in T2DM patients. The gene discussed is SLC47A1; the disease is type 2 diabetes mellitus.