PDCD1 and neoplasm: In addition, high expression of PD-1/PD-L1 in cancer cells and tumor infiltrating lymphocytes (TILs) was negative-correlated with lactate dehydrogenase 5 (LDH5) and positive-correlated with HK2 and monocarboxylate transporter 2 (MCT2) Thus, PD-1/PDL-1 accompanied with glycolysis related markers, such as LDH5, act as prognostic and immunotherapy-outcome predictors in NSCLC (Giatromanolaki et al., 2019).