While other TGF-β superfamily members like GDF15 have been proposed as potential markers for precision prevention of CRC with NSAIDs [18], the role for bone morphogenetic proteins (BMPs) and SMAD family proteins in NSAID chemoprotection are less well established than they are for other agents, like metformin [37], or other physiologic processes, like osteogenic differentiation [38,39]. This evidence concerns the gene GDF15 and colorectal carcinoma.