HIF1A and pheochromocytoma: However, loss-of-function mutations in the genes encoding SDH and FH have been related to several cancers, including pheochromocytoma, paraganglioma, and renal cell carcinoma, where the upregulation of HIF-1α is associated with metabolic reprogramming, highlighting the impact of dysregulated succinate and fumarate on HIF-1α activation [107–110].