CD8A and neoplasm: Of note, CD8+ TILs displayed equally high protein expression of CD44, TOX and PD-1 that did not differ among cells isolated from tumours in Ptger2−/−Ptger4fl/fl mice, Cd4crePtger2−/−Ptger4fl/fl mice and GzmbcrePtger2−/−Ptger4fl/fl mice (Extended Data Fig. 4c).