ERBB2 and lung cancer: For HER2 amplification positive lung cancer patients, adding trastuzumab to their chemotherapy regimen did not seem to bring more clinical benefit.22 However, it has been reported that trastuzumab or T‐DM 1 had an objective response rate (ORR) of 50.9% and PFS of 4.8 months in HER2 exon 20 mutated patients.17 In another cohort involving seven HER2 exon 20 insertion patients, five patients achieved a partial response or stable disease on T‐DM1 treatment.23 This could mean that trastuzumab or T‐DM1 might be beneficial to a minority of patients.