As keratins (notably K5, K7, K8/K18, K19, and K20) exhibit characteristic expression patterns in human tumors, and have great importance in immunohistochemical tumor diagnosis of carcinomas [6,28,29], it is thus possible that citrullination of histones, keratin and antithrombin are all involved in the tumorigenic process. The gene discussed is KRT20; the disease is carcinoma.