The increasing application of molecular genetic profiling has led to the recognition of rare subtypes that are defined by a specific pathogenetic mechanism e.g. fumarate hydratase (FH)-deficient RCC, succinate dehydrogenase (SDH)-deficient RCC (0.05–0.2%), TFE3-rearranged RCC, TFEB-altered RCC, ELOC-mutated RCC and ALK-rearranged RCC [6]. The gene discussed is FH; the disease is renal cell carcinoma.