PlGF-2 is an angiogenic factor that belongs to the cysteine-knot superfamily of growth factors. PlGF-2 is expressed in umbilical vein endothelial cells and placenta. It signals through the VEGFR-1/FLT1 receptor, and stimulates endothelial cell proliferation and migration. PlGF-2 also signals through Neuropilin (NP-1), and can bind with high affinity to heparin. Recombinant Human PlGF-2 is a 34.6 kDa disulfide-linked homodimeric protein of two 152 amino acid polypeptide chains.