QK is a peptide derived from the 17-25 alpha-helical region of vascular endothelial growth factor (VEGF), which is the region of VEGF involved when binding to its receptor Flt-1 (VEGFR-1), QK acts as a VEGF mimetic and agonist and can reproduce the biological activity of VEGF while retaining its bioactivity much longer in vivo than the full-length protein. QK promotes proliferation and angiogenic differentiation of endothelial cells and can promote microvascularization in vitro and in vivo. QK can be used as a VEGF mimetic agent in reparative angiogenesis and has been synthesised as a nanoparticle for enhanced stability, in this form it has been used to prevent the occurrence of bisphosphonate-related osteonecrosis of the jaw (BRONJ).