Additionally, several other factors, such as α5 and β3 integrins expressed by PCa cells and WISP1 (WNT1 induced secreted protein 1) expressed by osteoblasts at the local microenvironment, help in the homing of PCa by facilitating their adhesion and anchorage to the extracellular matrix of the bone [58,59]. Here, CCN4 is linked to posterior cortical atrophy.