A study on SIBP-01, a biosimilar trastuzumab for HER2-overexpressing breast cancer, showed that the geometric mean ratios (90% CI) of Cmax, AUC0-t and AUCinf were 93.55%–104.27%, 91.98%–102.35% and 91.88–102.34% respectively, they have PK similarity (Zhou et al., 2020). This evidence concerns the gene ERBB2 and breast cancer.