Human studies in patients with well-balanced glucose levels in diabetes mellitus type 2 subjects (with HbA1C levels of 7.2 ± 1.0%) (contrary to the abovementioned animal models with hyperglycemia and other metabolic diabetes-related alterations) demonstrated that the expression level of ABCB1 was not affected by the disease [45]. Here, ABCB1 is linked to diabetes mellitus.