Further, we investigated time course of probe accumulations in the tumor via whole-cell and cell-internalized radioisotope activities after the indicated varying incubation periods with the labeled ([18F]FB(ePEG12)12-exendin-4) probe, using INS-1 and HEK293/GLP-1R(+) cells, in which GLP-1R mRNA expressions were confirmed by quantitative PCR (Fig. 5A). This evidence concerns the gene GLP1R and neoplasm.