TNFSF11 and periodontitis: Monocyte lineage, the osteoclast precursors, may migrate to the sites of active bone resorption (e.g., alveolar bone in periodontitis) and differentiate into osteoclasts via macrophage colony-stimulating factor (M-CSF) and RANKL signaling, further aggravating periodontal bone loss (Hajishengallis and Chavakis, 2021).