title: Phylogenesis--ontogenesis--oncogenesis.
abstract: Ontogenesis might be considered as the development of phylogenetically consequent genic systems that mainly imply: homoeotic genes and ras protooncogene in segmentation; ras and myc protooncogenes in gastrulation; ras, myc and other nuclear protooncogenes in organogenesis; ras myc, other nuclear and cytomembrane protooncogenes in growth-differentiation. Oncogenesis is considered as the stable regression of a transformed cell into a "para-embryonal" gene-phenotypical condition, and it is usually presented as a three-phased process: mutational events on nuclear protooncogenes-myc in particular-would determine "initiation"; other mutations on cytomembrane protooncogenes-ras, especially-would determine "promotion"; other events would finally prevent the cell from carrying out its genic programme completely, thus maintaining the reiterated expression of primitive genic systems (gastrulation and organogenesis), the embryonal products of which-malignant in an adult organism-would determine tumoral "progression".
authors.forename: G
authors.initials: G
authors.lastname: Manzo
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D002455:Cell Division; D002471:Cell Transformation, Neoplastic; D008954:Models, Biological; D009374:Neoplasms, Experimental / Q000209:etiology*; D009857:Oncogenes; D010802:Phylogeny