Interestingly, the finding that in renal cell carcinoma, obesity is associated with a diminished efficacy of PD-1 blockade, has been ascribed, at least in part, to the presence of constitutively elevated IL-1β levels which can also frequently found in the microenvironment of cHL [21, 22]. The gene discussed is IL1B; the disease is obesity due to melanocortin 4 receptor deficiency.