Solute carrier family 7 member 11 (SLC7A11, also known as xCT), which is the substrate-specific subunit of cystine/glutamate antiporter protects cancer cells from oxidative stress and ferroptosis through upregulating cystine uptake and glutathione biosynthesis. The expression and activity of SLC7A11 is governed by diverse mechanisms, such as transcriptional regulation and posttranslational modification. In this commentary, we mainly summarize transcriptional regulation of SLC7A11 in both cancer cells and cancer stem cells and highlight ferroptosis-dependent functions of SLC7A11 in promoting tumor development.