MDK and cancer: Midkine displays a number of activities that might be relevant for cancer development, e.g., it has been demonstrated to act as a mitogen, an antiapoptotic, and angiogenic factor, a chemoattractant and haptotactic factor, an immunomodulator, and an inductor of synthesis of several cytokines and growth factors, such as IL-8, TGF-β, MIP-2, and MCP-1 [6, 7].