The Peutz-Jeghers syndrome (PJS) is an autosomal dominant disease (OMIM#175200) caused by a germline mutation of the serine/threonine kinase 11 (STK11) gene on chromosome 19p13.3.[1,2] PJS is characterized by mucocutaneous pigmentations, hamartomatous polyps in the gastrointestinal (GI) tract, and a significantly increased risk of various cancers, particularly in females.[1,2] The incidence of PJS is estimated to be between 1 in 50,000 to 1 in 200,000 live births.[3,4]. The gene discussed is STK11; the disease is cancer.