Many cancer cells upregulate the cystine-glutamate antiporter xCT (a dimer of SLC7A11 and SLC3A2) to resist ferroptotic cell death, and as a result, cancer cells often deplete cysteine from the TME (xCT imports cystine, a dimer of cysteines that is quickly converted to cysteine within the reducing environment of the cytoplasm in a reaction that consumes NADPH) [198]. Here, SLC3A2 is linked to cancer.