In K562/A02, a multidrug-resistant variant of CML K562 cells with GCS and Bcl-2 co-overexpression, apoptosis was enhanced by adriamycin (a chemotherapeutic agent used for treatment of various cancers) through downregulation of Bcl-2 via the ERK pathway. This evidence concerns the gene BCL2 and chronic myelogenous leukemia, BCR-ABL1 positive.