The codon 249 at TP53 is highly mutated in hepato cellular carcinoma (HCC), due to exposures of aflatoxin B1, whereas in lung cancers, TP53 mutations cluster at several codons, 157, 245, 248, and 273 due to exposures of tobacco smoke carcinogen metabolite, benzo-(a) pyrenediol-epoxide (BPDE). The gene discussed is TP53; the disease is lung cancer.