PTGS1 and Familial adenomatous polyposis: Thus, we aimed to conduct a biomarker-based clinical study in 8 FAP patients treated chronically with enteric-coated (EC) low-dose Aspirin (100 mg daily for three months) to explore whether it inhibits mainly platelet COX-1 or whether it can affect colorectal COX-1 and COX-2 or causes off-target effects.