Given the molecular and partialhistologic similarity to CCA, this potential subtype may be a distinct clinicalentity and strongly warrants further study into its most beneficial classification.Furthermore, the complete lack of IDH mutations in otherwisestandard HCC from the TCGA set (0/172) has implications about specific functions ofmutant IDH in modulating liver cell identity and also underscoresthe benefit of combined molecular and histopathological diagnosis. This evidence concerns the gene IDH2 and cholangiocarcinoma.