PDCD1 and neoplasm: Similarly, an increase in tumor-killing M1 macrophages, as well as quantitative and qualitative enhancement of CD8+ T cells, as indicated by increased IFN-γ, granzyme B, TNF-α, and IL-2 expression, was ascribed to the addition of a KD to an anti-PD-1 and/or anti-CTLA-4 treatment in prostate and colon cancers.