PDIA4 and esophageal squamous cell carcinoma: In addition, the ESCC biomarkers identified in previous studies (several ESCC tissues or cell lines), including ACTA2, TAGLN20, HSPA9, PDIA4, PLEC, POSTN, PSAP, and THBS121 were also covered in the Fudan cohort (Supplementary Data 3b).