Higher frequency of alterations in FGFR, IDH1, IDH2, BAP1, PBRM1, MCL1, CDKN2A, BRAF and BRCA1/2 are observed in iCCA, while KRAS, TP53, CDKN2B, SMAD4, ErbB2 (HER2), CTNNB1 and MLH1 mutations are more suggestive of eCCA (107, 108). Here, ERBB2 is linked to infantile convulsions and choreoathetosis.