SDHB and hereditary leiomyomatosis and renal cell cancer: FH, encoding the proximal downstream enzyme to SDH, is another mitochondrial tumor suppressor gene, the loss of which leads to hereditary leiomyomatosis and renal‐cell cancer (HLRCC).46 FH‐deficient leiomyomas (a benign neoplasm) are highly penetrant, while RCC occurs slightly less frequently.74 However, the RCC that develop are highly aggressive, leading to the early generation of distant metastases,74 similar to SDHB‐deficient tumors.