SLC7A11 encodes a cystine/glutamate antiporter that forms a heterodimer with SLC3A2 to mediate sodium-independent, electroneutral exchange of extracellular L-cystine for intracellular L-glutamate across the plasma membrane. This transport supplies cystine for glutathione synthesis, which protects cells from oxidative stress. SLC7A11 also inhibits ferroptosis—a form of regulated cell death driven by lipid peroxidation—through multiple mechanisms, including import of L-kynurenine and functioning as an atypical lysosomal proton transporter. Additionally, it mediates placental uptake of N-acetyl-L-cysteine, reducing oxidative stress and inflammation. SLC7A11 is frequently overexpressed in human cancers including breast cancer, hepatocellular carcinoma (HCC), glioblastoma, and bladder cancer, where it suppresses ferroptosis and promotes tumor growth 1. In breast cancer, metformin induces ferroptosis by reducing SLC7A11 protein stability through inhibition of UFMylation, and combining metformin with ferroptosis inducers synergistically suppresses cell proliferation 2. In HCC, the transcription factor ATF4 activates SLC7A11 expression to maintain glutathione production and block ferroptosis-dependent hepatocyte death, protecting against NASH-related hepatocarcinogenesis 3. Multiple post-translational modifications regulate SLC7A11 stability: SOCS2-mediated ubiquitination promotes ferroptosis and radiosensitization in HCC 4, while ZDHHC8-catalyzed palmitoylation stabilizes SLC7A11 and confers ferroptosis resistance in glioblastoma 5. Emerging therapeutics include ferroptosis inducers and PHGDH inhibitor NCT-502 in bladder cancer 6, arbutin targeting the FTO/SLC7A11 axis in non-alcoholic fatty liver disease 7, and tanshinone IIA suppressing the KDM1A/PIAS4/SLC7A11 pathway in breast cancer 8.