An illustrative example of isoform shift in different tumor stages involves the CPT1 (Carnitine Palmitoyltransferase 1) gene that physiologically resides at the outer mitochondrial membrane of normal cells and represents a site for intracellular regulation of lipid metabolism by transporting long-chain fatty acids into mitochondria for β-oxidation (together with CPT2 and Carnitine/Acyl-Carnitine Translocase) [80,81]. Here, CPT2 is linked to neoplasm.