STAT3 and breast cancer: We have previously demonstrated that TrkB induces breast cancer metastasis by activating the Janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) and phosphatidylinositol-3-Kinase (PI3K)/AKT signaling pathways [25], and suppressing runt-related transcription factor 3 (RUNX3) and kelch-like ECH-associated protein 1 (KEAP1) expression [17].