AMPK is a highly conserved heterotrimeric protein kinase found in all eukaryotes. The heterotrimeric complex exists as multiple isoforms and consists of a catalytic alpha subunit, which is stabilized by non-catalytic regulatory beta- and gamma- subunits. AMPK plays a vital role in maintaining cellular energy homeostasis and is activated by rising levels of AMP under conditions of hypoxia, ischemia, exercise, low glucose levels. AMPK may play an important role in the control of type 2 diabetes and metabolic syndromes. Recent studies suggest that AMPK functions as a suppressor of cell proliferation of both malignant and normal cells.