In addition, some rearrangements are complex, and do not yield the ABL/BCR fusion due to the involvement of a third chromosome in the rearrangement.     ///    "In the process of generating BCR-ABL fusion, the deletion of residual BCR or ABL occurs in 15-30 percent of CML patients. "    ///    Patients enrolled in our prospective study of prognostic significance will be followed up for disease free and overall survival in correlation with ABL-BCR deletion status.. 