ERBB2 and breast cancer: Preclinical data suggesting that HER2-positive breast cancer is particularly reliant on neoangiogenesis (Davidson et al. 1987; Epstein et al. 2002; Yen et al. 2000; Konecny et al. 2004) led to the initiation of several clinical trials that evaluated the combination of trastuzumab and bevacizumab.