USP7 and gastric cancer: These included 1) the ubiquitin E3 ligase KBTBD2, which regulates PI3K p85α regulatory subunit abundance27, 28; 2) GPX4, which uses glutathione to detoxify lipid free radicals and protect against ferroptosis29; and 3) the ubiquitin specific protease USP7, which removes a monoubiquitin group from PTEN to support its cytoplasmic subcellular localization30 and which protects gastric cancer cells from ferroptosis31 (Fig. 1e–f).