In vivo, PRDX4-positive staining was correlated with an increased rate of recurrence and reduced disease-free survival (DFS) in squamous cell carcinoma patients [23], while our recent studies in stage I lung adenocarcinoma found that the weak expression of PRDX4 combined with a high MIB-1 labeling index predicts shortened DFS [27] and the high expression of PRDX4 combined with EGFR mutation was positively correlated with a better prognosis [28]. The gene discussed is PRDX4; the disease is lung adenocarcinoma.