CD4 and colorectal carcinoma: Moreover, we found that CRC patients with high frequencies of CD4+FoxP3+Helios−PD-1+ and CD4+FoxP3+Helios−CTLA-4+ Treg subsets in PBMCs, but not in TILs or NILs, had significantly shorter DFS than patients with lower frequencies of these Treg subsets (Fig. 5A, B).