PDCD1 and neoplasm: High PD-1 and GITR expression levels have been also found in tumor-infiltrating lymphocytes among different cancer indications based on messenger RNA sequencing (mRNA-seq) analysis (University of California at San Francisco (UCSF) immunoprofiler initiative) and immunohistochemistry (IHC), as previously suggested (Extended Data Fig. 2a,b and Supplementary Table 1)24.