CNR1 and inflammatory response: This study found that bacterial inflammation decreased CB1 expression in human periodontal ligament (PDL) cells.19 However, it has been found that CB1 seems to be upregulated during gingival wound healing in rats.30 To clarify the underlying role of CB1 in MSCs in mediating periodontal tissue regeneration, we explored the function and mechanism of CB1 in the osteo/dentinogenic differentiation of PDLSCs under inflammatory conditions.