We transfected GPX3 knockout adenovirus (shGPX3), GPX3 overexpression adenovirus (oeGPX3), and corresponding control (Ctrl) into breast cancer (MDA-MB-231, BT-549), colorectal cancer (Lovo, SW480), gastric cancer (MKN45), and ovarian cancer (Ovcar-4) cell lines. This evidence concerns the gene GPX3 and breast cancer.