GSTA4 (glutathione S-transferase alpha 4) is a cytosolic detoxification enzyme that catalyzes the conjugation of reduced glutathione to electrophilic compounds, with particularly high efficiency for 4-hydroxynonenal (4-HNE) and other α,β-unsaturated aldehydes formed during oxidative stress 1. The enzyme functions as a homodimer and plays a crucial cytoprotective role by neutralizing reactive aldehydes that accumulate under oxidative conditions 2. GSTA4's mechanism involves direct conjugation of glutathione to toxic aldehydes, thereby preventing cellular damage from lipid peroxidation products 3. The gene is transcriptionally regulated by NRF2 and contains antioxidant response elements that activate expression during oxidative stress 4. GSTA4 has complex disease relevance, showing protective effects against atopic dermatitis recurrence through anti-inflammatory and antioxidant activities 4, and certain polymorphisms are associated with reduced lung cancer risk 5. However, GSTA4 overexpression paradoxically promotes hepatocellular carcinoma progression via AKT pathway activation 6. In pancreatic cancer, GSTA4 expression is downregulated and associated with better prognosis, suggesting tumor-suppressive functions in this context 7. The enzyme's ability to prevent ferroptosis by protecting against lipid peroxidation makes it clinically significant for conditions involving oxidative stress and inflammation.