IDH1 and cancer: Eight of the genes altered in BTCs reported by Valle et al22 were described as having evidence of therapeutic impact (evidence level 2A‐3B) in “biliary cancer” or “solid tumor” based on the clinical practice guidance for NGS in cancer diagnosis and treatment21; these include ERBB2 amplification (evidence level 2A), NTRK1 fusion (evidence level 2A), RNF43 mutation (evidence level 3A), CDK6 (evidence level 3B) and CDKN2B loss (evidence level 3B), FGFR2 fusion (evidence level 3B), IDH1, and IDH2 mutations (evidence level 3B), listed in Table 1.