CD274 and neoplasm: Moreover, RFA activates the immune response of T cells and induces adaptive immunosuppression, which is mainly manifested as inactivation of tumor-infiltrating T cells, amplification of Tregs and MDSCs in the tumor microenvironment, transformation of Th1 cells to Th2 cells, and induction of PD-L1 expression on the T cell surface after ablation [22].