Therefore, in this study, we aimed to investigate the followings in ESCC patients: (1) predict NACRT efficacy and clinical outcomes/prognosis according to the status of TXNRD1/HO-1 in pre-NACRT endoscopic biopsy specimens and (2) examine the correlation between NACRT resistance and the difference of antioxidant protein expression in pre- and post-NACRT specimens. The gene discussed is TXNRD1; the disease is esophageal squamous cell carcinoma.