Expression of the p53, mdm2  and  p21, c-myc,bcr/abl, bcr, bcl2, bax, gapdh, actin genes contributes to thetotal program of ex vivo regulation of the proliferation anddifferentiation of CML Ph + cells. This evidence concerns the gene TP53 and chronic myelogenous leukemia, BCR-ABL1 positive.