WT1 and leukemia: Despite WT1 originally recognized as a tumor suppressor, a growing body of experimental evidences indicates that WT1 has oncogenic function in leukemias and a variety of solid tumors e.g. colon cancer, head and neck squamous cell cancer (HNSCC), pancreatic cancer, salivary gland cancer [11], ovarian cancer [12-14], and lung cancer [15,16].