TP53 and glioblastoma: In view of the heterogeneity of glioblastomas with regard to MGMT and p53 status, the simultaneous administration of TMZ or procarbazine and CCNU according to the PCV protocol (procarbazine, CCNU, and vincristine) or concomitant treatment with TMZ and CCNU, according to Herrlinger et al. [163], is a reasonable strategy.