PDCD1 and lung cancer: In this study, we hypothesized that differences in the response of the PD-1 inhibitor among lung cancer patients was related to key genes and lymphocytes paracrine activation, and reanalyzed the PD-1 blockade responsing associated single-cell RNA sequencing (scRNAseq) data shared by Professor Zemin Zhang to investigate the cellular and molecular mechanisms for PD-1 blockades.