CD56dim NK cells represent around 90% of total PB NK cells and are characterized by the high expression of CD16 and a higher potential to kill tumor cells, while CD56bright NK cells express higher levels of CD94-NKG2A heterodimers and primarily produce large amounts of cytokines including IFN-γ and tumor necrosis factor (TNF)-α [51,52]. This evidence concerns the gene TNF and neoplasm.