Functional SHIP1 (inositol 5-phosphatase) regulates proliferation of hematopoietic cells negatively, thus it is accepted as a cancer suppressor, whereas its reduced expression or activity can lead to leukemogenesis, including chronic myeloid leukemia (CML) or AML. The gene discussed is INPP5D; the disease is chronic myelogenous leukemia, BCR-ABL1 positive.