In our study, SERPINA1 was the core gene in PPI and correlated with seven ERS-related genes including ERLEC1, VWF, EDEM2, DERL3, APOE, IL6, and CXCL8, suggesting that SERPINA1 may play an essential role in the pathological process of periodontitis. The gene discussed is SERPINA1; the disease is periodontitis.