Although there is a strong genotype-phenotype relationship regarding cancer-causing and non-cancer-causing HIF2α mutations, patients presenting with PPGL display a wide range of clinical outcomes, ranging from a single PPGL tumor and no polycythemia to multiple PPGL tumors with polycythemia to PPGL tumors comorbid with both polycythemia and somatostatinoma (Tarade et al., 2018). The gene discussed is EPAS1; the disease is neoplasm.