Mis-regulations of genetic and biochemical processes are at the root of cancer. And conversely, ‘the pathological illustrates the normal’. By way of background, a half century ago three molecular biological mechanisms for regulation of gene expression and function were discovered. One is enzyme induction, a mechanism by which production of a protein from a gene is controlled. The second is covalent modifications of proteins by phosphorylation, which can greatly increase or decrease their catalytic and binding activity and stability, especially in eukaryotes. Third is feedback inhibition by non-covalent binding of a small molecule to an enzyme’s non-catalytic but regulatory sites Thereby enzyme activities and the corresponding entire metabolic pathways are rapidly and sensitively regulated.