GPX4 is higher expressed in cancer tissues than normal and is negatively associated with prognosis of patients, through hypomethylation in the upstream of GPX4, and active epigenetic modifications at H3K4me3 (trimethylation of histone H3 at lysine 4) and H3K27ac (acetylation of histone H3 at lysine 27) in the transcription start site of GPX4, indicating that high level of GPX4 in cancer may resulted from epigenetic regulation. Here, GPX4 is linked to cancer.