As a signature marker for systemic inflammations, C-reactive protein (CRP) has been consistently shown to be the strongest factor associated with overweight and obesity in human epidemiological studies (Timpson et al., 2011) and was thought to be the consequence of obesity rather than the cause of obesity by a statistical approach (Timpson et al., 2011). Here, CRP is linked to obesity due to melanocortin 4 receptor deficiency.