The assumption that this lower HER2 expression could also stimulate tumor growth encouraged researchers to treat these patients with anti-HER2 agents like trastuzumab and trastuzumab emtansine, but the results from different clinical trials were largely negative, indicating an insufficient therapeutic effect (Burris et al. 2011; Fehrenbacher et al. 2020). Here, ERBB2 is linked to neoplasm.