However, both of the phenotypes contain IL-17A+Foxp3+ T cells, which are significantly increased in the ovarian cancer ascites when compared with matched peripheral blood from the same ovarian cancer patients (Fig. 7b), indicating that Th17–Treg cell plasticity coincides with Th17–Treg cell imbalance in the human cancer microenvironment. This evidence concerns the gene IL17A and ovarian cancer.