The genesp53, mdm2, p21, c-myc,bcr/abl, bcr, bcl2, bax,and gapdh participate in the regulation of cellproliferation and differentiation, apoptosis and cell distribution for the cellcycle ex vivo in the Ph+cells of chronic myeloidleukemia containing the Ph chromosome andbcr/abloncogene.Expression of these genes correlates with regulation of cell proliferation anddifferentiation by alternating proliferation and maturation stages for threemain Ph+cell types that occur under chronic myeloid leukemia. The gene discussed is BCR; the disease is chronic myelogenous leukemia, BCR-ABL1 positive.