To demonstrate the distribution of alterations in TP53, PTEN, and CDKN2A/CDKN2B genes, an oncoplot was generated with the cBioPortal online tool [55,56], based on TCGA (The Cancer Genome Atlas, Pan-Cancer Atlas) data from 585 GBM patients and the search criteria set for any identified genetic alteration in the genes of interest. The gene discussed is PTEN; the disease is glioblastoma.