CD8A and neoplasm: The absolute number of effectors PD-1+ CD8 T cells, defined as SLECs (KLRG-1+ / IL7Rα-) and MPECs (KLRG-1- / IL-7Rα+) were significantly augmented in tumor infiltrates of HVEM KO tumors compared to that of HVEM WT tumors (Figure 5A, upper panel).