ROS1 and breast cancer: However, the successful approval of TKIs to treat ROS1-, RET-, NTRK1-, PDGFR-α, and AXL-rearranged NSCLC is vitally important as it sets the example for approval of TKIs to treat the same RTK-rearranged common epithelial tumors such as colon, gastric, and breast cancers (25).