The current study revealed that 6.8% of HER2-positive breast cancer patients experienced cardiotoxicity during neoadjuvant dual anti-HER2 therapy, which was within the range of cardiotoxicity reported in previous studies (Mantarro et al., 2016; Schneeweiss et al., 2018; Swain et al., 2018; Al-Saleh et al., 2022; Huang et al., 2022; de Azambuja et al., 2023). The gene discussed is ERBB2; the disease is breast cancer.