The leptin gene was identified in 1994.6 In one year later, adiponectin was found as the most abundant adipokine and count for 0.01% or 3–30 μg/ml of total plasma protein.7–10 In comparison with leptin research, however, until the recent 8 years, adiponectin has been attracted much attention particularly in the fields of pathophysiology and genetics of type 2 diabetes (T2D), obesity and diabetic nephropathy (DN). Here, LEP is linked to obesity due to melanocortin 4 receptor deficiency.