HIF1A and rheumatoid arthritis: Several studies have highlighted how accumulation of intracellular succinate stabilizes HIF-1α leading to the expression of angiogenic and pro-inflammatory genes in inflammatory innate immune cells, such as macrophages and dendritic cells27,35,45 Extracellular succinate is also relevant for inflammatory processes and many studies have explored the pro-inflammatory potential of high levels of succinate on inflammatory macrophages, which contributes to disease aggravation e.g., in rheumatoid arthritis or cancer27,29,35,46,47.