INS and obesity due to melanocortin 4 receptor deficiency: In consistency with the observations in the case-control study, in this study, PC2-Z was associated with obesity (OR = 1.18; 95%CI 1.05–1.34, P = 9.3 × 10−3), BMI percentile, fat mass percentage, insulin, and TG and levels (all P < 0.05; Supplemental Table 5).