As a consequence, melatonin shows a negative correlation with circulating insulin levels, with the suppression of pineal melatonin, as in night-shift work, leading to hyperinsulinemia, insulin resistance, and hyperleptinemia as well as a significant decrease in glucose transporter (GLUT)4 levels, which are characteristic of type 2 diabetes [40,41]. The gene discussed is INS; the disease is Insulin resistance.