FH and renal fibrosis: Adam et al. (2011) provided solid evidence asserting the absence of Hif/Phd pathway and introducing nuclear factor-like 2 (NRF2) dysregulation as an oncogenic pathway involved in FH-associated disease. Interestingly, FH inactivation also engages in renal fibrosis. Reduction of FH caused the accumulation of fumarate, leading to fibrosis in DN in Goto–Kakizaki (GK) rats. Increased levels of HIF-1α and TGF-β1 were detected, suggesting candidate mechanisms accounting for such fibrosis (Miura et al., 2019).