GSH is reported as one of the most important antioxidants in living organisms, which functions as a critical scavenger of reactive oxygen species (ROS) particularly lipid ROS.[30, 31, 32] GSH metabolism plays an important role in tumor progression, and elevated levels of GSH are associated with increased metastasis.[33] Recent studies reported that the cystine/glutamate antiporter system Xc‐/GSH/glutathione peroxidase 4 (GPX4) axis is a critical pathway involved in regulating ferroptosis, a newly defined form of programmed cell death (Figure 3C). The gene discussed is GPX4; the disease is neoplasm.