Carcinoembryonic antigen is a tumor marker, and it is one of the earliest tumor markers discovered, and it is very low in the protein secreted by normal adult cells. If it is much higher, for example, 100-200ng/mL or more, you should go to the oncology department. If it is much higher, for example, above 100-200ng/mL, you should go to the oncology department immediately and improve a series of imaging tests. If it is only mildly elevated, say 6-7ng/mL, it is possible that some benign inflammation of the digestive tract, or other people who smoke regularly, may also have this transient elevation, so don’t be too nervous. However, if you have to go to the hospital to register, you usually go to the oncology department.