MRPL52 promoted hypoxia adaptation and apoptotic resistance of BC cells by facilitating mitophagy to delay the onset of the vicious cycle between mitochondrial damage and ROS generation under hypoxia; At the same time, MRPL52 mediated hypoxia-induced ROS generation within a window, which further activated the ROS-Notch1-Snail signaling pathway to mediate the EMT and metastasis of hypoxic BC cells. The gene discussed is NOTCH1; the disease is breast cancer.