Detection of cfDNA in plasma samples could also guide potential mutational-based therapeutic interventions as de novo multiple point mutations in FGFR2 kinase domain were detected in cfDNA, primary tumours and metastases from patients with CCA with acquired resistance to the pan-FGFR inhibitor BGJ398 (ref.254). The gene discussed is FGFR2; the disease is cholangiocarcinoma.