CXCL12 and posterior cortical atrophy: In PCa bone metastases, because the bone matrix is a reservoir rich in cytokines, we suspect that there are other cytokines that could also contribute to enzalutamide resistance, such as IL8, stromal cell-derived factor 1 (also known CXCL12), and granulocyte colony-stimulating factor, which have been identified in cancer drug resistance (89).