ERBB2 and lung adenocarcinoma: This is explained by the fact that HER2‐altered lung adenocarcinoma has a much lower programmed death ligand‐1 (PD‐L1) and tumor mutational burden (TMB) expression than other mutations, leading to a suppressive tumor immune microenvironment (TIME) and hyporesponsiveness to immunotherapy in these patients [12, 13].