PDCD1 and obesity due to melanocortin 4 receptor deficiency: A 2020 study by Sanchez et al. reported that in a cohort of 129 RCC patients treated with anti-PD-1, anti-PD-L1, or anti-PD-1+anti-CTLA-4, obesity (BMI ≥ 30 kg/m2) tended to improve OS (49.9 months with obesity versus 15.5 months without) (HR 0.54; 95% CI [0.31-0.95]), although this association was not significant after controlling for International Metastatic RCC Database Consortium (IMDC) risk score (HR = 0.72; 95% CI [0.40-1.30]) (32) (Table 1).