As a leukemic model we used NB4, an APL cell line expressing PML/RARα, K562, a CML cell line expressing M-BCR-ABL1 as positive control and U937, an AML cell line as negative control for AXL-RTK expression at transcriptional level [25]. This evidence concerns the gene AXL and chronic myelogenous leukemia, BCR-ABL1 positive.