IDO1 and periodontitis: Additionally, we identify critical tissue-specific differences, including the predominance of IL-36 signaling in COPD, IL-17-carrying NETs in systemic lupus erythematosus (SLE) and pulmonary fibrosis, and specialized fibroblast subpopulations, such as IDO1+ cells in CRSwNP and TNFRSF21+ cells in periodontitis.