Since PTEN is mutated in autosomal inherited disorders with phenotypes similar to those of PJS (Bannayan-Riley-Ruvalcaba syndrome and Cowden disease), there appears to be a functional link between the proteins involved in different hamartomatous polyposis syndromes, thus, emphasizing the central role played by LKB1 as a tumor suppressor in the intestine [14]. This evidence concerns the gene STK11 and Cowden disease.