SLC38A7 and glioma: Because gliomas have upregulated amino acid transporters and increased amino acid metabolism, and labelled amino acid tracers, including 11C-MET, 18F-FET, and 18F-FDOPA, are increasingly being widely used in gliomas in recent years with better tumour-to-background contrast for differentiation glioma grade, biopsy guiding, radiotherapy planning, therapy monitoring, and differentiation between TrE and residual or recurrent glioma [21–23].