ERBB2 and breast cancer: For instance, NDGA increases the susceptibility of prostate and colorectal tumor cells to TRAIL-induced apoptosis by up-regulating the expression of the death receptor 5 (Yoshida et al., 2007), and was also shown to sensitize refractory breast cancer cells to trastuzumab, a monoclonal antibody against HER2 (Rowe et al., 2008).