In conclusion, this study employed bioinformatics techniques, including WGCNA, to identify five characteristic genes associated with cSCC: ADH1B, CCL27, ID4, LRP4 and S100A9. Additionally, we demonstrated that CCL27, ID4, LRP4 and S100A9 are correlated with the infiltration of various immune cell types in cSCC. Here, S100A9 is linked to skin squamous cell carcinoma.