FLT4 and neoplasm: In addition, C/EBP-δ regulates gene expression, including VEGFR3 in lymphatic endothelial cells [21], platelet-derived growth factor receptor (PDGFR) in vascular smooth muscle cells [7, 14, 32], insulin-like growth factor-I in osteoblast cells [4, 11], CXCR4 and HIF-1α in tumor cells and macrophages [1, 2].