The univariate Cox regression analysis revealed that age (hazard ratio [HR], 1.538; 95% confidence interval [CI], 1.047–2.259; P = .028), N stage (HR, 2.129; 95% CI, 1.420–3.193; P = .000), and PDGFA expression (HR, 1.565; 95% CI, 1.065–2.300; P = .023) were prognostic factors affecting the OS of ESCC patients (Table 4). Here, PDGFA is linked to esophageal squamous cell carcinoma.