CLOCK and obesity due to melanocortin 4 receptor deficiency: Numerous studies have shown that disturbed sleep or an impaired circadian clock make individuals more vulnerable to hypertension, type 2 diabetes mellitus (T2DM), hyperlipemia, obesity, atherosclerosis, and cancer (e.g., lung, breast, liver, pancreas, ovary, colon, and prostate cancers) [9-12], meanwhile they also induce oxidative stress, promote inflammatory responses, and accelerate coagulatory responses [13].