To test whether CE accumulation occurs in BCR-ABL mutation-independent IM resistant CML, the K562R cell line was established.[21] This cell line was rendered imatinib-resistant by BCR-ABL independent mechanisms, and is grown without loss of viability in 1μM imatinib. This evidence concerns the gene ABL1 and chronic myelogenous leukemia, BCR-ABL1 positive.