MYC and neoplasm: Although pathologically increased MYC levels occur in many human cancers and enforced high-level Myc is tumorigenic in experimental models, it remains unclear whether low levels of Myc can sustain tumorigenesis or whether supra-physioloigcal levels of Myc are essential to amplify the programs of whichever oncogenes and mutant tumor suppressors are operating in cells on the path toward malignancy (22).