Since its discovery as a cytosolic metabolic kinase that purified with and inhibited Acetyl Co-A carboxylase (the rate limiting enzyme for long chain fatty acid synthesis) (Lent and Kim, 1982), we have come a long way to have discovered the many facets of AMPK function in cellular and systemic metabolism, regulation of cell cycle, longevity, stress resistance, tumor pathology, circadian rhythm among other functions. The gene discussed is PRKAA2; the disease is neoplasm.