Nilotinib, a second-generation TKI, is 30-fold more potent than imatinib in binding to BCR-ABL in treatment-resistant CML and 5 to 7-fold more potent than imatinib in imatinib-sensitive leukemia cells [221]. Here, ABL1 is linked to chronic myelogenous leukemia, BCR-ABL1 positive.