Of greater concern, cancer cachexia, which manifests as muscle wasting and weight loss, among others, is associated with poor immunotherapy efficacy, possibly due to the desensitizing effects of PD-1/PD-L1 inhibitors (Morimoto et al. 2021; Op den Kamp et al. 2012; Smith et al. 2011). The gene discussed is PDCD1; the disease is cancer.