The neuroendocrine tumours pheochromocytomas and paragangliomas carry the highest degree of heritability in human neoplasms, enabling genetic alterations to be traced to clinical phenotypes through their transmission in families. Mutations in more than a dozen distinct susceptibility genes have implicated multiple pathways in these tumours, offering insights into kinase downstream signalling interactions and hypoxia regulation, and uncovering links between metabolism, epigenetic remodelling and cell growth. These advances extend to co-occurring tumours, including renal, thyroid and gastrointestinal malignancies. Hereditary pheochromocytomas and paragangliomas are powerful models for recognizing cancer driver events, which can be harnessed for diagnostic purposes and for guiding the future development of targeted therapies.