HMOX1 and rheumatoid arthritis: Due to the significance of HIF-1α, AMPK/SIRT1, PI3K/Ak, and Nrf-2/HO-1 in the inflammatory response and immune cell responses, pharmacologically targeting these signal pathways has been considered a treatment of many different immune-mediated diseases, including sepsis, IBD, RA, cancer, and autoimmune encephalomyelitis [140–143].