In an analysis of ctDNA from patients with advanced gastrointestinal stromal tumors, researchers found that, following imatinib therapy, patients with KIT exon 11 plus 17 and/or 18 alterations had superior progression-free survival (PFS) and overall survival (OS) when they received ripretinib as a second-line treatment compared with sunitinib; patients with KIT exon 11 plus 13 and/or 14 alterations had superior PFS and OS with sunitinib compared with ripretinib. The findings highlight the clinical value of molecular testing.