ERBB2 and lung cancer: In 2004, Erb‐B2 Receptor Tyrosine Kinase 2(HER2/ERBB2) kinase domain mutations were identified in non‐small cell lung cancer (NSCLC).6 It has been reported that HER2 mutations could promote cell proliferation and motility in vitro and was essential in tumorigenesis and maintenance in vivo.7, 8 HER2 mutations in NSCLC were dominated by in‐frame insertions in exon 20 of HER2 kinase domain, with the most common subtype being A775_G776insYVMA.9 For advanced NSCLC patients harboring HER2 mutations, the median overall survival was reported to be approximately 19 to 22.9 months.10, 11