These included (1) the ubiquitin E3 ligase KBTBD2, which regulates PI3K p85α regulatory subunit abundance35,36; (2) GPX4, which uses glutathione to detoxify lipid free radicals and protect against ferroptosis37; and (3) the ubiquitin specific protease USP7, which removes a monoubiquitin group from PTEN to support its cytoplasmic subcellular localization38 and which protects gastric cancer cells from ferroptosis39 (Fig. 1e, f). This evidence concerns the gene PIK3CA and gastric cancer.