IDH2 and brain neoplasm: This research was led by Cooks et al. and evolved from demonstrating the ability of DESI-MSI to discriminate between types of brain tumor in adults, such as oligodendroglioma, astrocytoma, and oligoastrocytoma, up to the validation of DESI-MS for target detection of 2-hydroxyglutarate (2-HG) in a large human glioma cohort of adult subjects, for intraoperative isocitrate dehydrogenase (IDH) mutation assessment [52,53,54,55,56,57].