TNFSF11 and periodontitis: Together, these results show that activation of the TLR2-MYD88-RANKL axis in osteocytes and mature osteoblasts is responsible for alveolar bone resorption in periodontitis due to Pg. Further, the data indicate that osteocytes and mature osteoblasts are the primary source of RANKL in Pg-induced periodontitis and that RANKL from T/B lymphocytes has little effect on osteoclastogenesis in the periodontitis model.