The common types of leukemia are acute leukemia, chronic granulocytic leukemia, and chronic lymphocytic leukemia. Patients with acute leukemia generally have an average survival time of only 3 months without special treatment. With the current aggressive treatment, a number of patients can survive for a long time. In particular, acute lymphoblastic leukemia has the best prognosis if the age is 1-9 years old and the white blood cell count is <50×10^9/L. If complete remission is followed by aggressive consolidation and maintenance therapy, about 60% of patients can survive for a long time or even be cured. However, the prognosis of acute lymphoblastic leukemia in adults is not as good as that in children, with a survival rate of only about 30% for more than 3 years. However, the prognosis of M3, or acute promyelocytic leukemia, in acute myeloid leukemia is very good for most patients if early death can be avoided, with 80% of patients being cured. For patients with chronic granulocytic leukemia, the median survival is about 3 years, with some entering the accelerated phase in 3-5 years, and a few patients can survive for 10-20 years. In contrast, the duration of chronic lymphocytic leukemia varies, with some patients surviving up to 10 years or more, and others only 2-3 years.