On the other hand, the E2100 Study [17] that is a pivotal study of combined therapy using paclitaxel and bevacizumab (the PB regimen) in patients with human epidermal growth factor receptor 2 (HER2)-negative MBC demonstrated the efficacy and safety of the regimen as first-line chemotherapy for the study population, and its independent blind review [18] validated them; however, the incidence of grade 3/4 peripheral neuropathy was as high as 23.6%. Here, ERBB2 is linked to peripheral neuropathy.