STK11 and neoplasm: These findings closely followed another major revelation that the tumor suppressor LKB1 (Liver Kinase B1; also known as Serine/Threonine Kinase 11 - STK11) is a direct activator of AMPK [14-17], and that defects in cell polarity precede the development of tumors (pancreatic ductal adenocarcinoma) in genetically modified mice with tissue-specific deletion of LKB1 [18].