However, whereas the numbers of differentiated TIM-3+ TILs were low in control BRAFV600E tumours in WT mice and Ptger2−/−Ptger4fl/fl mice, they were highly abundant in Cd4crePtger2−/−Ptger4fl/fl mice (Extended Data Fig. 7c) and indistinguishable from those found in Ptgs1/Ptgs2−/− BRAFV600E tumours in WT mice. Here, PTGS1 is linked to neoplasm.