PDCD1 and neoplasm: Woroniecka et al. (2018) observed the poor function of infiltrated T cells in the tumor microenvironment of glioblastoma. In localized clear cell renal cell carcinoma, the intratumoral infiltration of exhausted CD8+ T cells with high levels of PD-1, Tim-3, and Lag-3 was investigated (Giraldo et al., 2017).