STK11 and neoplasm: Primary cilia also regulate β-cell size and polarity through ciliary proteins like LKB1 (liver kinase B1), a serine-threonine kinase and tumor suppressor that mediates cellular energy sensing and metabolism through AMPK (AMP-activated protein kinase) phosphorylation (Granot et al., 2009a; Boehlke et al., 2010).