CD4 and neoplasm: The fact that CD8+ T cells from CD4-cre x IKKβfl/fl tumor-bearing mice could produce IFN-γ in response to PMA/ionomycin suggests that tumor-specific IKKβ-deficient T cells may be anergic or hyporesponsive despite their initial proliferation, as anergic T cells have defects in Ras signaling which can be functionally rescued by bypassing early steps of T cell activation [46].