The binary logistic regression model showed that age > 70 years; smoking history; diabetes history; prolonged use of perioperative antibiotics; and elevated CRP, IL-6, and IGF-1 levels on the 1st day after surgery were risk factors for postoperative lung infection in elderly patients with LC (P < .05) (Table 3). The gene discussed is CRP; the disease is laryngotracheoesophageal cleft.