The reported frequencies of GLP-1R-producing phaeochromocytomas vary: five out of six (9) and 12 out of 20 (8), both with ligand receptor autoradiography; we found GLP-1R in six of the 20 tumours with immunohistochemistry and the corresponding transcripts in almost half of 182 tumours with RNA sequencing. This evidence concerns the gene GLP1R and pheochromocytoma.