CD8A and neoplasm: Survival of patients with MPM is longer when tumors are highly infiltrated by cytotoxic CD8+ T cells (tumor-infiltrating lymphocytes), whereas PD-L1 expression is associated with shorter survival (median OS 5.0 in patients who are PDL1-positive vs. 14·5 months PDL1-negative patients; p < 0.0001) (81, 82).