CD4 and keloid: As shown in Figure 6A, the keloid tissue has more immune cell infiltration than the control group, including memory CD4/8+ T cells, Type 1/2/17 helper cells, dendritic cells, macrophages, etc. GSEA analysis further showed that the keloid tissues were enriched in Th cells (FDR=0.019, P=0.039), Th1 cells (FDR=0.021, P=0.018), Th2 cells (FDR=0.022, P=0.031) and Th17 cells (FDR=0.017, P=0.001) pathways (Figures 6B, 2E).