In the Iowa Women’s Health Study, smoking was associated with the microsatellite-instability–high, CpG island methylator phenotype–positive, and B-Raf protein encoding gene (BRAF) mutation–positive subtypes of CRC, which indicates that epigenetic modification may be functionally involved in smoking-related colorectal carcinogenesis (33). The gene discussed is BRAF; the disease is colorectal carcinoma.