We further explored the association between sex and PON-arylesterase in T2D by dividing the activity into quartiles based on the distribution in the control group, and by comparing the odds of being diagnosed with T2D of subjects with activity lower than < 110.9 kU/L (the IV quartile cut-off) with those within the higher activity quartile (>110.9 kU/L). This evidence concerns the gene PON1 and type 2 diabetes mellitus.