PDCD1 and nonpapillary renal cell carcinoma: The results showed that immune checkpoint markers (HAVCR2, CTLA4, TIGIT, CD274, LAG3, PDCD1) were significantly correlated with NCKAP1 expression; TMB and MSI were considered prognostic markers to predict response to immunotherapy in CCRCC (Pang et al., 2016).