The mTOR signaling pathway is implicated in PJS, due to germline mutations in STK11, by the presence of mucocutaneous pigmentation in some patients [117], and in Cowden syndrome, by the presence of glycogenic acanthosis of the esophagus and skin lesions in some patients who carry germline mutations in PTEN [118]. This evidence concerns the gene STK11 and Peutz-Jeghers syndrome.