In breast cancer, the antioxidant enzyme peroxiredoxin-1 (PRDX1) has been studied as a possible biomarker and therapeutic target because its downregulation significantly impaired the proliferation rate of breast cancer cells and tumor growth in an in vivo model of xenotransplanted PRDX1-deficient MCF-7 cells. This evidence concerns the gene PRDX1 and neoplasm.