The semi-quantitative analysis results further showed that compared with healthy gingiva, the expression of iNOS-positive areas in periodontitis group increased to 3.79 times, CD86 increased to 3.36 times, TGF-β increased to 8.37 times, CD206 increased to 4.31 times, and PGRN increased to 19.43 times (Fig. 1B). This evidence concerns the gene MRC1 and periodontitis.