Enhanced mitophagy is also observed in esophageal squamous cell carcinoma and lung cancer.286,287 Conversely, deletion or loss-of-function mutations in Parkin are detected in lots of tumors, including glioblastoma, ovarian cancer and breast cancer cells included, which leads to deficient mitophagy and elevated mitochondrial ROS levels.288–290 ROS can stabilize HIF-1α and activate glycolysis, promoting the Warburg effect and tumor progression.291–294 Therefore, how cancer cells adapt to hypoxic conditions may depend on the cell type. Here, PRKN is linked to cancer.