Diabetes mellitus is characterizedby hyperglycemia due to a reductionin insulin secretion and/or insulin resistance.64 In patients with diabetes, serum furin is decreased, relativeto individuals with normal plasma glucose levels,65 indicating the association between lower serum furin levelsand the risk of pre-diabetes and diabetes.65 Similarly to what is seen in hypertension, a study with 4 yearsof follow up found that non-diabetic individuals with DNA hypermethylationof the promoter region of the FURIN gene might havean increased risk of diabetes (Table 2).66 Here, FURIN is linked to diabetes mellitus.