CD274 and periodontitis: Notably, previous reports have demonstrated similar findings in a periodontitis model using transgenic mice overexpressing PD-L1 in gingival basal keratinocytes, where PD-L1 overexpression reduced ligation-induced inflammation in periodontal tissues and alveolar bone resorption.[35] Additionally, Por phyromonas gingivalis upregulates PD-L1 expression but suppresses the inflammation in periodontal tissues, which is consistent with the results of our study.[36]