Chronic granulocytic leukemia, also known as chronic myeloid leukemia, is a myeloproliferative tumor originating from pluripotent stem cells. It is characterized by a specific chromosomal alteration, commonly referred to as the Philadelphia chromosome, which is formed by the translocation of chromosomes 9 and 22, resulting in the formation of the BCR-ABL fusion gene at the molecular level. Chronic granulocytic leukemia is a clonal disease originating from pluripotent stem cells. Due to a significant expansion of the progenitor cell pool, there is excessive proliferation of myeloid cells and increased granulocyte production. The slow clearance of granulocytes leads to the accumulation of granulocytes in the body, which is the main cause of the disease.