CTLA4 and neoplasm: Specifically, some studies have shown that Treg FOXP3+ cells display a tumor-protective effect [32, 33] in FL [34] and DLBCL [34, 35] by suppressing T-cell proliferation and IFN-γ production [31, 36], while others found that Treg cells co-expressing activating markers such as CTLA4 [37] and TIGIT [38] result in an enhanced suppressive property and are associated with poor prognosis [39].