While a third group did not find reduction of absolute Treg numbers in cancer tissues, the relative ratio of FOXP3+ cells over CD4+ T cells among patients receiving Ipilimumab was reduced when compared with either pre-treatment biopsy samples or compared with those that received another anti-CTLA-4 antibody, Tremelimumab, which is IgG2 isotype with less ADCC potential (167, 170) and has not been shown to be effective in phase III clinical trials (171). This evidence concerns the gene CTLA4 and cancer.