LKB1 - A master tumour suppressor of the small intestine and beyond

Peutz-Jeghers syndrome (PJS) is a rare, inherited intestinal polyposis syndrome that is associated with a significantly increased risk of several types of cancer - particularly those of the gastrointestinal and reproductive systems. Most cases of PJS have been associated with loss-of-function mutations in the ubiquitously expressed LKB1 gene, which encodes a serine/threonine kinase. Recent studies have begun to illustrate the molecular mechanisms by which LKB1 functions as an important new tumour suppressor.