CD4 and neoplasm: The Peli1-deficient CD4 and CD8 T cells are hyper-responsive to TCR/CD28 stimulation for production of IL-2 and IFNγ and display reduced sensitivity to inhibition by Treg cells and TGFβ.94 The Peli1-deficient mice display stronger tumor-suppressive ability compared to wildtype control mice, associated with enhanced tumor infiltration with CD8 effector T cells (unpublished data).