Increases in lipid peroxidation can cause ferroptosis, a form of cell death triggered by inhibition of glutathione peroxidase 4 (GPX4), which catalyzes the reduction of lipid peroxides and is a target of ferroptosis inducers, such as erastin. The alpha6beta4 integrin protects adherent epithelial and carcinoma cells from ferroptosis induced by erastin. In addition, extracellular matrix (ECM) detachment is a physiologic trigger of ferroptosis, which is evaded by alpha6beta4. The mechanism that enables alpha6beta4 to evade ferroptosis involves its ability to protect changes in membrane lipids that are proferroptotic. Specifically, alpha6beta4-mediated activation of Src and STAT3 suppresses expression of ACSL4, an enzyme that enriches membranes with long polyunsaturated fatty acids and is required for ferroptosis. Adherent cells lacking alpha6beta4 require an inducer, such as erastin, to undergo ferroptosis because they sustain GPX4 expression, despite their increase in ACSL4. In contrast, ECM detachment of cells lacking alpha6beta4 is sufficient to trigger ferroptosis because GPX4 is suppressed. This causal link between alpha6beta4 and ferroptosis has implications for cancer biology and therapy.