VHL and hereditary pheochromocytoma-paraganglioma: In recent years, in vitro experiments on PC12 cells have suggested that the von Hippel–Lindau (VHL) protein might participate in the molecular cascade leading to apoptosis of sympathetic progenitor cells and that impairment of this protein could predispose to pheochromocytomas, a tumor of the adrenal gland, in adulthood (Lee et al, 2005).