PTEN and glioblastoma: This is also an outcome of PTEN deficiency as DNA replication and mitotic spindle formation are hindered.81 Genetic alterations in PTEN are seen in greater frequencies amongst HPV-positive patients with oral squamous cell carcinomas, in comparison to patients testing HPV-negative.82,83 Whilst somatic PTEN mutations are seen in various cancers, there is greater emphasis on endometrial cancers and glioblastomas.84