IDH, isocitrate dehydrogenase; NEC, not elsewhere classified; FDG, fluorodeoxyglucose; MET, methionine; PET, positron emission tomography; SUVmax, maximum standardized uptake value; T/N ratio, the ratio of SUVmax in tumor to SUVmax in contrast normal tissue; MRI, magnetic resonance imaging. Here, IDH3A is linked to neoplasm.