MCP-1 may facilitate monocyte aggregation and could play a regulatory role in the microbiota of rosacea patients.[46] PD-L1 binds to PD-1 receptors on the surface of T cells, inhibiting their activation and proliferation and thus downregulating the immune response.[47] However, there remains a lack of studies investigating the association between MCP-1, PD-L1, and rosacea to validate the findings of this study. This evidence concerns the gene CCL2 and rosacea.