Regarding the effect of Tregs, several preclinical studies indicated that the anti-tumor effects of CTLA-4 blockade were dependent on the depletion of CTLA-4-expressing Tregs in the tumor microenvironment via antibody-dependent T cellular cytotoxicity, leading to an increase in the CD8+/Treg ratio (70). This evidence concerns the gene CTLA4 and neoplasm.