The importance of STAT3 in promoting bone metastasis in PCa is highlighted by the fact that that conditioned medium from PC3 PCa cells induces the production of chemokines and cytokines from osteoblasts that promote osteoclast generation and that STAT3 in osteoblasts is detectable in bone biopsies from patients with osteolytic metastases [110]. This evidence concerns the gene STAT3 and posterior cortical atrophy.