GSTM1 and type 2 diabetes mellitus: Dadbinpour et al. reported no significant relationship between GSTT1 genotype and the presence of DR in T2DM (p = 0.187) but reported a significant association between GSTM1 genotype and DR (p = 0.04), results in contradiction with a study highlighting that GSTM1 null genotype might confer protection against DR in Caucasians with T2DM [36].