What is leukemia, leukemia (leukemia) is a type of malignant clonal hematopoietic stem cell disease. Out of control because of leukemia cell proliferation, differentiation, barriers, etc., remain blocked apoptosis in different stages of cell development, leading to leukemia cells in bone marrow and other hematopoietic tissues proliferated accumulate and infiltrate other organs and tissues, so that inhibition of normal hematopoiesis, organ involved and organizational dysfunction. According to the differentiation of leukemia cells, maturity and natural course of disease, the acute and chronic leukemia is divided into two categories. Acute leukemia (acute leukemia, AL) cell differentiation arrest in the original cells and immature cells in the early stages of disease progression is rapid, the natural course of only a few months. Chronic leukemia (chronic leukemia, CL) cell differentiation arrest in more mature cell stage, the disease develops slowly, the natural course of up to several years. According to the main cells involved in the AL series can be further divided into acute non-lymphocytic leukemia (acutenonlymphoblastic leukemia, referred to as acute leukemia, Fei Lin, ANLL) and acute lymphoblastic leukemia (acutelymphoblastic leukemia, referred to as acute lymphoblastic leukemia, ALL).What is leukemia, chronic leukemia, chronic myeloid leukemia are divided into (chronicmyeloid leukemia, referred to as CML, CML) and chronic lymphocytic leukemia (chroniclymphoblasticleukemia, referred to as CLL, CLL) and so on.