CD4 and neoplasm: The role of NF-kB in the tumor immune response is ambivalent, depending on the type of immune cells infiltrating the tumor, so that its increased expression in CD4+ lymphocytes is correlated to the regulatory T cell subtype development and to the inhibition of anti-tumor immune response [41], while anergic CD8+ T cells, associated with impaired antitumor immunity, present ablated NF-kB activation [42].