CCL4 and neuroblastoma: The analyzed NB samples could secrete pro-inflammatory cytokines (CCL2, CCL4, CCL5, CCL8, CXCL10, etc.); produce PTGS2, which induces the synthesis of prostaglandins (PGE2); and modulate the microenvironment by interacting with collagens (COL6A2, COL6A3, COL12A1, COL14A1, COL5A1, COL5A2, etc.), which maintain and regulate the fluidity of the extracellular matrix (ECM).