CXCR4 and neoplasm: For instance, in Epithelial_cells−>Monocyte, Tissue_stem_cells−>Monocyte, T_cells−>Monocyte, tissue stem cells−>Monocyte, Endothelial_cells−>Monocyte, and Epithelial_cells−> T_cells, various signal pairs are involved, such as MIF-(CD74+CD44) and MIF- (CD74+CXCR4), Macrophage migration inhibitory factor (MIF) promotes the proliferation and survival of tumor cells by binding to CD74 and CD44.