STK11 was identified in 1998 as a novel tumor suppressor gene in patients with Peutz-Jeghers syndrome (PJS) [1], an autosomal, dominant disorder characterized by the presence of pigmented macules on the skin and mouth, coupled with the growth of benign polyps in the gastrointestinal tract [2]. Here, STK11 is linked to Peutz-Jeghers syndrome.