D-I03 is a promising RAD52 inhibitor, showing the highest inhibitory effect on D-loop formation in vitro on several BRCA1/2-deficient cell lines (Capan-1, MDA-MB-436, and UWB1.289) and on BRCA1-deficient BCR-ABL-positive CML cells from patients. Here, ABL1 is linked to chronic myelogenous leukemia, BCR-ABL1 positive.