RET and paraganglioma: Regarding paragangliomas/pheochromocytomas, it is currently accepted that there are 2 distinct tumorigenesis clusters according to their transcriptional profile: a pseudohypoxic cluster (associated with mutations in VHL/SDHx/EGLN1 genes) and a kinase receptor-signaling cluster (associated with RET/NF1/TMEM127/MAX/KIF1B mutations) [144].