[Growth factors and oncogenes in brain tumors: the model of glioblastoma and medulloblastoma].

Glioblastomas and medulloblastomas are models for studying the implication of growth factors and oncogenes in tumor development. Amplification and/or hyperexpression of oncogenes result in products that may mimic growth factors and/or their receptors; cells may demonstrate autocrine and/or paracrine activity. Prognostic implications of such findings are suggested.