CXCR4 and breast cancer: The growth factor inhibitor DCN (decorin), which was previously shown to be decreased in BC compared to benign lesions (Franzén et al., 2018), interacts with IGF1R, EGFR, VEGFR2, ERBB2, and MMP7 (www.proteomicsdb.org), and studies also indicated that DCN may affect signaling via the chemokine receptor CXCR4 and is needed for autophagy.