[Explicative models of cancer biology: an enlarged vision]

The second half of the 20th century has been dominated by genetic models of tumors that provided conceptual tools explaining tumor genesis and its evolution. Other domains--epigenetics, cell metabolism--appeared that generated a more complex landscape of tumor physiopathology. Moreover, the discovery of tumor stem cells and intratumoral heterogeneity are likely to explain recurrence. A major difficulty is that every tumor behaves as an organ that evolves in function of its microenvironment. By integrating all the new data in more and more sophisticated models, the major goals may emerge from the characterisation of new markers for diagnosis and prognosis and from the selection of pertinent and efficient new therapeutic targets.