ALK and non-small cell lung carcinoma: Fueled by advances in the field of ALK-positive non-small cell lung cancer (NSCLC), where ALK fusions constitute the predominant driving oncogenic event and where the initial response is frequently followed by the development of acquired resistance, second- and third-generation ALK inhibitors soon became available, including ceritinib, brigatinib, entrectinib, and lorlatinib.