STK11 and neoplasm: LKB1 also regulates activation of adenosine monophosphate kinase (AMPK), essential to help maintain metabolic homeostasis during periods of increased cellular activities and reduced ATP levels (Alexander and Walker, 2011; Sebbagh et al., 2011), as occurs in rapidly dividing tumor cells (Han et al., 2013) as well as in activated lymphocytes (Shaw et al., 2004).