GSTM1 and type 2 diabetes mellitus: Hori et al (94) did not reveal a significant association between T2DM and GSTT1/M1 gene alleles, but the incidence rate of T2DM in GSTT1 and GSTM1 null genotypes was 1.5-fold higher than that in GSTM1 and GSTT1 positive genotypes.