CD4 and neoplasm: Interestingly, tumor antigen-specific CD4+ and CD8+ T cells retrovirally transduced to express the dominant negative TGFβRII each provided enhanced tumor control when transferred into B16 melanoma-bearing mice, but no therapeutic benefit resulted when adoptively-transferred T cells had been transduced with retrovirus encoding soluble “decoy” TGFβRII proteins that could neutralize TGFβ1 signaling not only in T cells, but also in bystander cell populations [150].