CTLA4 and neoplasm: Anti-mouse CTLA-4 antibodies have been shown to effectively reduce Tregs in the tumor microenvironment [45,46]; although a recent report suggests that Treg depletion does not occur with anti-CTLA-4 therapy (ipilimumab or tremelimumab) in humans and that opportunity exists to modify Fc portions of the CTLA-4 antibodies to achieve Treg depletion [47].