In another study, CXCL8 upregulated PCa cell expression of bone sialoprotein (BSP), an extracellular bone matrix protein, and increased PCa invasion and adhesion to bone chips in vitro, showing PCa cells can contribute to bone remodeling by producing bone matrix proteins and that CXCL8 has a role in this process as well as in the process of PCa metastasis to bone (52). This evidence concerns the gene IBSP and posterior cortical atrophy.