GSTM1 (glutathione S-transferase mu 1) is a phase II detoxification enzyme that conjugates reduced glutathione to hydrophobic electrophiles, protecting cells from oxidative stress and toxic compounds 1. The enzyme plays crucial roles in cellular protection through multiple mechanisms, including inhibition of lipid peroxidation and ferroptosis pathways 2. GSTM1 enhances STAT3 phosphorylation, upregulating glutathione peroxidase 4 (GPX4) expression and reducing reactive oxygen species production, thereby preventing fibroblast activation and cardiac fibrosis following myocardial infarction 2. The gene exhibits a common deletion polymorphism (GSTM1 null genotype) that results in complete loss of enzymatic activity and is associated with increased disease susceptibility 1. GSTM1 deficiency significantly increases risk for multiple cancers, including prostate cancer 3 and esophageal carcinoma 4, particularly in Asian populations. The null genotype also predisposes individuals to symptomatic neurocysticercosis by reducing antioxidant capacity 5. Additionally, age-related DNA hypermethylation of GSTM1 in T lymphocytes leads to decreased expression and impaired Th1 cell differentiation, potentially compromising immune function in elderly individuals 6. These findings highlight GSTM1's critical role in cellular protection and disease prevention.