GSTM1 and type 2 diabetes mellitus: Heme-related absorbance levels (Abs398) were increased by 57% in T2D patients vs. controls (0.508 vs. 0.324, p<0.001 respectively) (Fig 1A) and Hb-related absorbance (Abs575) levels by 60% (0.040 vs. 0.025, p = 0.003 respectively) (Fig 1B) in univariate analyses.