IDH1 mutations, which are common in gliomas, acute myeloid leukemia, intrahepatic cholangiocarcinomas, sinonasal undifferentiated carcinomas, enchondromas, and chondrosarcomas, have also been identified in intestinal cancers.51-54 Hartman et al52 found that IDH1-mutated intestinal cancers were more common in IBD-related adenocarcinomas in comparison to sporadic cases and were associated with a low-grade tubuloglandular histology. Here, IDH1 is linked to sinonasal undifferentiated carcinoma.