Spontaneous tumor regression could potentially be initiated by immune factors such as tumor necrosis factor-α, tumor growth factor-β, α-interferon, and natural killer cells; induction of differentiation; hormonal mediation; elimination of a carcinogen; tumor necrosis or apoptosis; angiogenesis inhibition; and external factors such as biopsy, infection, trauma, and surgery [11]. This evidence concerns the gene TNF and infection.