A lesson learned from PTK-targeted therapies in chronic myeloid leukemia (BCR-ABL)[46-48] and NSCLC (EGFR mutants, ALK and ROS1 fusions)[49-53] is that the secondary mutations in the targeted PTK can cause resistance to the TKIs. Here, PTK2B is linked to chronic myelogenous leukemia, BCR-ABL1 positive.