MAPK8 and periodontitis: Moreover, since the JNK signaling pathway has been associated with the regulation of macrophages' biological function and the JNK/JUN/NCOA4 axis has been found to regulate the ferroptosis of various cell types, we conducted further research to determine the role of the JNK/JUN/NCOA4 axis in modulating the chronic apical periodontitis course by regulating macrophage ferroptosis.