PPP1R21 and obesity due to melanocortin 4 receptor deficiency: The allele C rs10454142 PPP1R21 has a risk value for BC in obese women (allelic model: CvsT, OR = 1.52, 95%CI = 1.10–2.11, p = 0.012, and pperm = 0.013; additive model: CCvsTCvsTT, OR = 1.71, 95%CI = 1.15–2.62, p = 0.009, pperm = 0.011, and power = 92.16%); dominant model: CC + TCvsTT, OR = 1.95, 95%CI = 1.13–3.37, p = 0.016, pperm = 0.017, and power = 82.98%) and is not associated with the disease in the cohort of women without obesity (Table 2).