CTLA4 and renal cell carcinoma: Herein, R54 impaired PB-RCC-Tregs function reducing frequency of Nrp-1+Tregs/CTLA-4+Tregs, reducing immunosuppressive cytokines (IL-35, IL-10, and TGF-β), T effector proliferation, Tregs migration, DMR of TSDR and FOXP3 and DNMT1 transcription.