CXCR4 and neoplasm: Furthermore, hypoxia-induced expression of bone-homing molecules such as CXCR4, integrin αvβ3, and PIM kinases enhances tumour cell adhesion to bone matrix components and eases extravasation into the bone marrow niche, where they interact with osteoblasts and osteoclasts to establish osteoblastic or mixed lesions [20,21,22].