Liver kinase B1 (LKB1), also known as serine/threonine kinase 11 (STK11), was originally identified as a susceptibility gene of Peutz-Jeghers syndrome (PJS), an inherited disorder characterized by gastrointestinal tract polyps and predisposition to developing cancers [8–10]. This evidence concerns the gene STK11 and Peutz-Jeghers syndrome.