ERBB2 and breast cancer: Dysregulation of this complex pathway has also been linked to chemotherapy resistance, such as the monoclonal antibody Trastuzumab (Herceptin) in HER2-overexpressing BC (Liu et al. 2020; Paplomata and O'Regan 2014; Yu et al. 2015). Recent studies show that inhibition of the PI3K/AKT pathway shows strong potential as a treatment avenue for BC, specifically, HER2 positive subtypes (Kaklamani et al. 2019; Verret et al. 2019).