p53 binds directly to the let-7a3 and let-7b gene enhancer and represses let-7a and let-7b expression in HCT116 colon cancer cells in response to radiation and oxidative stress, while NF-κB induces expression from the let-7a/b endogenous promoter by binding to the basal let-7 promoter [30], [31]. This evidence concerns the gene TP53 and colonic neoplasm.