GPX7 (glutathione peroxidase 7) is a non-selenium-containing glutathione peroxidase family member with unique cellular functions extending beyond canonical antioxidant activity. Unlike other GPx family members, GPX7 lacks detectable GPx catalytic activity but functions as a redox stress sensor and transmitter, shuttling disulfide bonds to regulate diverse signaling proteins including GRP78, PDI, CPEB2, and XRN2 in response to oxidative stress 1. GPX7 localizes to the endoplasmic reticulum lumen and cytoplasm, where it protects esophageal epithelia from hydrogen peroxide-induced oxidative stress and suppresses acidic bile acid-induced reactive oxygen species [UniProt]. The protein also plays roles in unfolded protein response and redox homeostasis maintenance 1. Clinically, GPX7 is significantly upregulated in multiple malignancies. In hepatocellular carcinoma, GPX7 shows statistically significant overexpression correlating with tumor grade 2. In papillary thyroid carcinoma, high GPX7 expression promotes cell proliferation while inhibiting apoptosis through caspase activity modulation 3. Pan-cancer analysis reveals GPX7 overexpression as an independent prognostic factor in lower-grade glioma, where elevated expression associates with poor overall survival and predicts temozolomide sensitivity 4. GPX7 deficiency in mice results in ROS accumulation, elevated cancer incidence, autoimmune disorders, and obesity 1. These findings position GPX7 as both a potential diagnostic/prognostic biomarker and therapeutic target across multiple cancer types.