As an important regulator in the cellular antioxidant system, ORAOV1 in ESCC cells protects the tumor cells from ROS-induced damage by binding to pyrroline-5-carboxylate reductase (PYCR) (Togashi et al., 2014), which can directly scavenge ROS and upregulate the level of antioxidant enzymes (Krishnan et al., 2008). Here, PYCR1 is linked to esophageal squamous cell carcinoma.