PKM and glioblastoma: Employing positron emission tomography (PET) tracer [18F]DASA-23, which comprises 1-((2-fluoro-6-[18F] fluorophenyl)sulfonyl)-4((methoxyphenyl)sulfonyl)piperazine, visualization of aberrant expression of PKM2 in cell culture, mouse models of glioblastoma multiforme (GBM), healthy human volunteers and patients with GBM have been reported [34].