From the figure, it can be seen that SLC2A3, MEFV, FPR2, TREM1, and IL1B are significantly distributed in the neutrophil cluster in this dataset, then the difference analysis was done for normal and periodontitis groups in the neutrophil cluster by ggplot2 package (Figure 8B; Supplementary Figure S3), the results showed that SLC2A3, FPR2, TREM1, IL1B were differential, with SLC2A3 being the most significant. This evidence concerns the gene TREM1 and periodontitis.