Despite this, gastrointestinal adverse events (AEs) are frequently reported, and no clinical-radiological and endoscopic features and their impact in terms of treatment discontinuations, interruptions, and dose reductions have been described so far.<h4>Case report</h4>A 37-year-old never-smoker woman was treated in our institution with selpercatinib for a <i>RET</i> fusion-positive NSCLC. This evidence concerns the gene RET and non-small cell lung carcinoma.