PCSK1 and obesity due to melanocortin 4 receptor deficiency: However, the PCSK1 rs6234 G-allele showed a significant association with increased risk of combined phenotype of obesity and overweight (OR 1.21[1.03–1.43], P = 0.0193) (P for SNP-gender interaction  = 0.11) and a trend toward association with increased obesity risk (OR 1.25[0.98–1.61], P = 0.08) (P for SNP-gender interaction  = 0.0458) in men, but not in women (P≥0.29) in the gender-stratified analyses (Table 2).