MDK and neoplasm: Midkine is also involved in initiation or progression of many pathological status, such as tumor invasion [5] rheumatoid arthritis [6], experimental autoimmune encephalitis [7], adhesion after surgery [8], neointima formation of the blood vessel [9], hypertension [10], and renal injury after ischemia [11], exposure to chemotherapeutic reagent [12] and diabetes [13].