The role of ketosis in cancer is related to the following mechanisms: (1) reduction of glucose and insulin, decreasing glucose availability to the tumor; (2) modulation of oxidative stress; (3) reduction of inflammation; (4) enhancement of anti-tumor immunity; (5) alteration of gene expressions, reducing the expressions of genes involved in the hypoxic response, angiogenesis, and invasive potential; and (6) sensitization of tumors to standard of care and adjuvant therapies [111]. This evidence concerns the gene INS and cancer.