CD8A and cancer: We, and others, have shown that a variety of factors influence responsiveness to CPI, including tumor mutation burden22–25, somatic copy-number alterations (CNA)25,26, antigen processing and presentation27, CD8+ T cell tumor infiltration28,29, presence of B cells and tertiary lymphoid structures30,31, spatial relationships between immune and cancer cells32, presence of specific functional immune cell subsets33, and characteristics of the gut microbiota34–36.