New and emerging targets in cholangiocarcinoma. ARID1A, AT-rich interaction domain 1A; BAP1, BRCA1-associated protein 1; BRAF, v-raf murine sarcoma viral oncogene homolog B1; BRCA, breast cancer gene; ERK, extracellular signal-regulated kinase; FGFR2, fibroblast growth factor receptor 2; HCQ, hydroxychloroquine; HER2, human epidermal growth factor receptor 2; IDH, isocitrate dehydrogenase; KGDH, alpha ketoglutarate dehydrogenase; KRAS, Kirsten rat sarcoma virus; MDM2, mouse double minute 2; MEK, mitogen-activated protein kinase; NTRK, neurotrophic tropomyosin receptor kinase; PDH, pyruvate dehydrogenase; PK CK2, protein kinase CK2; RAF, rapidly accelerated fibrosarcoma; RAS, rat sarcoma virus; RET, rearranged during transfection; TGF-β1, transforming growth factor beta 1.