NOX4 and rheumatoid arthritis: Zhou et al. (2022) showed a significant increase in levels of ACSL4 and NOX4, whereas a significant decrease in GPX4 levels was observed in cartilage of RA patients. Similar results were observed in the adjuvant arthritis (AA) rat model, indicating an association between enhancement in ferroptosis of chondrocytes and RA progression. As opposed to other studies, Ling et al. (2022) reported a decrease in ACSL4 expression and an increase in FTH1, GPX4, and SLC7A11 expression, thereby indicating a reduction in ferroptosis in RA-synovium and FLS.