CTLA4 and neoplasm: The in vivo effect of a-CTLA4-TGFβRII on Tregs was examined in human melanoma tumor-bearing NSG mice (NOD/Shi-scid IL-2rgnull) that were immune reconstituted with tumor-matched human leukocyte antigen (HLA) A2 + human CD34+ bone marrow (BM) cells.