In 34 patients with RET altered NSCLC treated on the phase 1 trial of selpercatinib, 44% of patients had clearance of the RET driver alteration detected by NGS at cycle one (day 15) and 79% had at least a 50% decrease in ctDNA, supporting the clinical activity of the drug [40]. Here, RET is linked to non-small cell lung carcinoma.