ROS1 and small cell lung carcinoma: Small cell lung cancer (SCLC) transformation has been reported in 3–14% of patients treated with first- and second-generation EGFR TKI, and in 5–20% of those receiving Osimertinib [23,24] and has also been observed in ALK- and ROS1-rearranged tumors, suggesting that it is independent of TKI class [25,26].