ALK and carcinoma: Aggressive radioiodine-resistant carcinomas with tyrosine kinase gene fusion can now be treated with specific molecularly targeted drugs, such as pralsetinib or selpercatinib for RET-rearranged tumors, larotrectinib for NTRK-rearranged tumors, and entrectinib for ALK- and ROS1-rearranged tumors, and testing for tyrosine kinase gene rearrangement is often requested to pathology laboratories (2, 75).