In line with the observation that both TFH and TFR cells (group 2 genes) expressed checkpoint receptors (Pdcd1, Ctla4, Lag3 and Tigit) and the aforementioned drivers of long-term memory, GSEA-NES analysis revealed alignment with gene signatures of CD8+ T cell precursors and progenitors of exhausted cells from chronic infection and cancer and signatures associated with long-term hematopoietic stem cell memory relative to Teff cells (Fig. 3f). This evidence concerns the gene PDCD1 and cancer.