IDH2 and undifferentiated carcinoma: Considering the epigenetic roles of DNA methylation related to IDH mutation [6], chromatin remodeling associated with SWI/SNF alterations [8], and our findings of activated chromatin remodeling, histone modification, and DNA methylation pathways, alongside the rarity of genetic alterations, it appears that SNUC and similar undifferentiated carcinomas arising in the sinonasal tracts predominantly employ epigenetic mechanisms in their carcinogenesis.