In the former cancers, the low expression of CPS1 leads to exaggerated production of ammonia, which may result in reactive oxygen species (ROS) creation, adenosine monophosphate-activated protein kinase (AMPK) phosphorylation and hyperactivation of the AMPK–fatty acid oxidation (FAO)–forkhead box protein M1 (FOXM1) axis. The gene discussed is CPS1; the disease is cancer.