CD274 and obesity due to melanocortin 4 receptor deficiency: Factors that promote immunosuppressive mechanisms, particularly that of PD-1/PD-L1 pathway during adaptive immune responses in settings of obesity or HFD, remain to be elucidated, and better understanding of the mechanism by which obesity impairs priming though the PD-1/PD-L1 pathway will shed important light on cancer and infection management in obese patients.