The FACS trial included 1202 patients who had undergone curative surgery for colorectal cancer Dukes stages A to C in 39 hospitals across the United Kingdom.13 In the FACS trial, the patients were divided into 4 groups: minimum follow-up only, CEA testing only, CT scan only, or CEA testing and CT scan. The gene discussed is CEACAM5; the disease is colorectal cancer.