RET and non-small cell lung carcinoma: Multi-kinase inhibitors (MKIs) targeting commonly altered oncogenic drivers, such as EGFR, MET, KIT, and VEGFR2, have shown moderate selectivity against altered RET in NSCLC and were thus repurposed as RET inhibitors (discussed below) (132–136), with many of these inhibitors displaying intracranial activity against brain metastases (137–139).