In P25, T1 and T3 have a shared EGFR L858R mutation, and T3 also has a TP53 p. R175H, but T2 had an EGFR 19del mutation that was different from other lesions, indicating that the patient’s three lung adenocarcinomas were independent primary tumours (Figure 3D). The gene discussed is EGFR; the disease is lung adenocarcinoma.