As tumours progressed, the frequency of CD4+ FoxP3-T-bet- TILs decreased but still accounted for 55% of total CD4+ TILs in D21 tumours, while TH1 (FoxP3-T-bet+) and TREG (FoxP3+T-bet-) subsets remained relatively stable (Figure 7A). Here, CD4 is linked to neoplasm.