CXCL12 and neoplasm: Fibroblasts in bladder cancer parietal tissue promote bladder carcinogenesis and progression by paracrine secretions of CXCL12 into TME to interact specifically with CXCR4 receptors (a specific receptor for CXCL12, expressed in T cells and macrophages in tumor tissues) and promote the proliferation of depleted T cells in cancer tissues (16).