ITGB4 and breast cancer: Gene expression analysis showed that GPNMB+ cells significantly upregulated genes involved in invasion and/or tissue remodeling, including EGFR, a direct interactor of GPNMB in breast cancer cells (Lin et al, 2016), its downstream targets (STAT3, MMP 2-3-9) and ITGB4, TGFβ, VEGF and VCAM (Appendix Fig. S9H).