Seventy-four percent of patients had a tumor harboring a KIAA1549::BRAF fusion; 10% had a chromosomal rearrangement involving BRAF (as detected by fluorescence in situ hybridization or in situ hybridization and presumed to represent a KIAA1549::BRAF or other BRAF fusion); and 16% had a BRAF V600E mutation. The gene discussed is BRAF; the disease is neoplasm.