In 2024, a study by Niki M. Moutsopoulos’ group (164) at the NIH demonstrated that epithelial cell-derived IL-23 is the initiator of inflammation in periodontitis, promotes the oral mucosal immune response to microbial components of the bacterial flora (e.g. flagellin, etc.), and serves as a mediator of inflammation in the subsequent development and regression of periodontitis. The gene discussed is IL23A; the disease is periodontitis.