As we all known, insulin resistance (IR) is closely related to obesity, hypertension, hyperlipidemia, as well as other metabolic syndrome (MetS) symptoms. HOMA-IR index, a means for detectingβ-cell function and IR, is widely used at present, but it has limited value in subjects receiving insulin treatment or those who do not have functioning beta cells [30]. The gene discussed is INS; the disease is obesity due to melanocortin 4 receptor deficiency.