PDCD1 and cancer: These include increased plasma levels of the pro-inflammatory cytokines TNF-α and IL-6, and, in particular, those of the soluble inhibitory immune checkpoints, CTLA-4, PD-1, PD-L1, LAG-3 and TIM-3, together with a high prevalence (42%) of elevated levels of high-sensitivity CRP in the setting of decreased levels of vitamin D. These changes are indicative of ongoing, chronic inflammation and seemingly intense immunosuppression, which accompany, and may precede, the development of many types of cancer (31, 32).