The b2a2 variant cell lines KCL-22 and BV-173 displayed higher levels of p210BCR-ABL protein (163.1% and 168.2 +/- 77.6(SD)%, respectively) than the b3a2 CML cell lines LAMA-84 and K562 (128 +/- 61.3(SD)% and 100.0 +/- 18.7(SD)%, respectively). This evidence concerns the gene ABL1 and chronic myelogenous leukemia, BCR-ABL1 positive.