They could also work as positron emission tomography (PET) biomarkers (or radiotracers) [24] for glioma progression by non-invasively and selectively detecting mut-IDH1 expression (PET is a molecular imaging technique which uses specific probes that are labeled with positron-emitting radioisotopes to visualize and measure changes in biological processes in vivo. Here, IDH1 is linked to central nervous system cancer.