In this study, we have used two genetically distinct paediatric glioblastoma cell lines KNS42 and SF188, to identify whether a combination of the dual pan-Class I PI3K/mTOR inhibitor PI-103 [13–15] with TMZ would result in metabolic changes detectable by NMR spectroscopy, with potential to be used as a non-invasive method of monitoring response in early phase and subsequent clinical trials in children with glioblastoma. The gene discussed is MTOR; the disease is glioblastoma.