Such tumors are usuallyaggressive and similar to primary glioblastomas in their molecularcharacteristics (aberrations in EGFR, PTEN, NF1, CDKN2A/B).The third group, for which the prognosis turned out to be intermediate betweenthe two, includes mutIDH in the absence of 1p/19q codeletion. The gene discussed is PTEN; the disease is glioblastoma.