Molecularly targeted approaches have shown efficacy in specific genomic subsets: FGFR inhibitors (pemigatinib, infigratinib) for FGFR2 fusion-positive iCCA [7], IDH inhibitors (ivosidenib) for IDH1-mutated iCCA [8], and HER2-directed therapies (such as zanidatamab) for HER2-high cholangiocarcinoma and HER2-amplified GBC [Level 2]. The gene discussed is IDH1; the disease is cholangiocarcinoma.