DACT2 and breast cancer: Based on those reports, this research was performed to explore the impact of macrophage-derived exosomal miR-503-3p in biological processes of BC cells via modulating DACT2 and Wnt/β-catenin signaling pathway, and we inferred that the inhibition of macrophage-derived exosomal miR-503-3p may contribute to malignant behaviors of BC cells through targeting DACT2 and activating Wnt/β-catenin signaling pathway.