The inhibition of FANCD2 foci in Mo7e-p210 cells and in primary CML cells could result from either a direct effect of the BCR/ABL oncogene, or through accumulated mutations that may have occurred along the culture of the cell line or during the progression of the disease of CML patients. This evidence concerns the gene ABL1 and chronic myelogenous leukemia, BCR-ABL1 positive.