Cytokines and their receptors are also polymorphic, and subtle genetic variations or single nucleotide polymorphisms (SNPs) predominantly found in the promotor region of genes such as IL-1β, 1-Rα, -2, -6, -10, -12, -13, -16, -18, TNF, IFN-γ, TGF-β are linked to functional changes and correlate with increased susceptibility to infections, autoimmunity, certain cancers and their differing treatment outcomes (65–67). This evidence concerns the gene TNF and cancer.