STAT3 and breast cancer: Copper directly activates oncogenic signaling pathways, leading to the expression of key proteins such as HIF1α, GPER, and VEGF in breast cancer, and promoting tumorigenesis and angiogenesis.[4, 12] Recent studies have highlighted the role of copper in the immune regulation of breast cancer, including the upregulation of PD‐L1 expression via activation of the STAT3 and EGFR signaling pathways, which enable immune evasion.[4, 13]