To address this issue, we adopted the HER2 amplification criteria for breast (Wolff et al. 2018) and gastric cancer (Cutsem et al. 2015) as reference and established three FISH positive criteria: (1) HER2/CEP17 ≥ 2.0 and HER2 ≥ 4.0; or HER2 ≥ 6.0; (2) HER2 ≥ 5.0; (3) HER2 ≥ 4.0 (Fig. 2a). Here, ERBB2 is linked to gastric cancer.