In contrast, serum CTRP9 levels were significantly higher in patients with obesity than in the lean group, and was down regulated after weight loss surgery, which was inconsistent with previous studies (Wong et al., 2009; Wei et al., 2014), suggesting that CTRP9 may play a compensatory role in obesity (Wolf et al., 2016). Here, C1QTNF9 is linked to obesity due to melanocortin 4 receptor deficiency.