ERBB2 and non-small cell lung carcinoma: The 12-base pair (bp) in-frame insertion A775_G776insYVMA (YVMA), resulting in duplication of four amino acids Tyrosine-Valine-Methionine-Alanine (Tyr-Val-Met-Ala) in exon 20, is observed the most frequent HER2 alteration variant in NSCLC, which is accounting for approximately 60–70% of HER2 exon 20 insertions (ex20ins) (Shigematsu et al., 2005; Perera et al., 2009; Arcila et al., 2012; Liu et al., 2018; Jebbink et al., 2020).