A recent study of triple-negative breast cancer reported that copper-enriched SOX2/OCT4+ cells showed much higher sensitivity than other cells to copper depletion and suggested that metabolic reprogramming of a select population of SOX2/OCT4+ metastatic cells in a way that leads to copper depletion could be a novel antimetastatic therapy (13). This evidence concerns the gene POU5F1 and triple-negative breast carcinoma.