The proposal that platelet activation is a causal event of both cancer and cardiovascular disease is further supported by our recent results of enhanced systemic biosynthesis of TXA2, mainly from platelet COX-1, in colorectal cancer and in familial adenomatous polyposis (FAP), a colon cancer syndrome caused by mutations in one of two genes: APC and MUTYH [13,14]. The gene discussed is MUTYH; the disease is Familial adenomatous polyposis.