CEACAM5 and neoplasm: Moreover, thymol administration (20 mg/kg/day, p. o.)to male Wistar rats showed promising protective effects against colon cancer by significantly reducing elevated serum levels of colon-related tumor markers, carbohydrate antigen 19-9 (CA 19-9) and carcinoembryonic antigen (CEA), as well as the apoptotic marker, caspase-3 compared to the colon cancer group [74].