Preclinical investigations have uncovered that opioids such as morphine can trigger tumor proliferation, suppress apoptosis, enhance angiogenesis, and facilitate the invasion of cancer cells through various mechanisms, including EGFR phosphorylation in lung cancer [12], activation of the MAPK/ERK pathway in endothelial cells in breast cancer [13], and induction of urokinase plasminogen activator secretion in colon cancer [5]. Here, PLAU is linked to breast cancer.