SLC7A11 is a sodium independent, chloride-dependent anionic L-cystine/L-glutamate antiporter on the cell surface.7 Intracellular cysteine is generally produced de novo or re-utilized through protein degradation.8–10 However, in oxidative stress, de novo biosynthesis or a catabolic supply of cysteine is not sufficient to meet the high requirement for antioxidant synthesis by cancer cells. This evidence concerns the gene SLC7A11 and cancer.