Decreased TNF-α (Fig. 3L) and IFN-γ (Fig. 3M) expression was observed in adoptively transferred tumor-infiltrating CD8+ T cells in Rag1−/− mice challenged with Id2fl/flCd4-Cre+ CD8+ T cells plus Id2fl/flCd4-Cre− CD4+ T cells. Here, CD4 is linked to neoplasm.