ABL1 and chronic myelogenous leukemia, BCR-ABL1 positive: To investigate imatinib-resistance, we performed quantitative mass spectrometry comparing the proteome and phosphoproteome of K562 cells (a standard CML model) and ImR cells, an imatinib-resistant K562 derivative that also exhibits cross-resistance to second- and third-generation BCR-ABL tyrosine kinase inhibitors.