Indeed, the frequency of complex or large alterations and of low-allele-fraction mutations is high (18 cases carrying at least one of the two; 13.2% of all KIT/PDGFRA-mutant patients), thus further highlighting the need for centralization of GIST molecular diagnosis at least for WT cases, since these alterations would have probably been missed by routine molecular analyses. The gene discussed is KIT; the disease is gastrointestinal stromal tumor.