BCR and chronic myelogenous leukemia, BCR-ABL1 positive: During targeted therapy, most patients carrying the driver genetic alterations (e.g., EGFR mutations in non-small cell lung cancer (NSCLC) and fusion protein BCR/ABL in CML) would respond to corresponding targeted agents thus be benefited, while some patients do not respond well and thus are considered to experience primary or intrinsic resistance.