Taken together, the CDK4’s putative role as prognostic marker and the higher expression of CDK4 and EXT2 in PBZ samples we observed, together with the increasing expression of both genes in GBM compared with normal brain tissues, observed by consulting the databases, may suggest a driven role of both genes in the preliminary steps of PBZ malignant transformation. The gene discussed is CDK4; the disease is glioblastoma.