Consistent with our findings on afatinib, a series of studies had reported that afatinib showed limited activity for HER2 ex20ins in NSCLC (De Grève et al., 2012; Liu et al., 2018; Nagano et al., 2018; Dziadziuszko et al., 2019; Lai et al., 2019; Fang et al., 2020). The gene discussed is ERBB2; the disease is non-small cell lung carcinoma.