Most notably, their research has shown that obesity leads to T cell dysfunction which results in greater expression of programmed death 1 (PD-1) receptor and increased effectiveness of the blockade between PD-1, and programmed death ligand-1 (PD-L1), which accounts for greater efficacy of anticancer therapy with PD-1/PD-L1 inhibitors and results in the higher patients’ survival rate. Here, PDCD1 is linked to obesity due to melanocortin 4 receptor deficiency.