The grade of pheochromocytoma and paraganglioma, known as the GAPP score, is based on tumor pathology, cellular properties, acne-like necrosis, vascular or cystic infiltration, Ki67 index, and type of catecholamine secretion, with a maximum score of 10. The gene discussed is MKI67; the disease is hereditary pheochromocytoma-paraganglioma.