ERBB2 and breast cancer: ErbB-2-positive breast cancer is currently treated with therapeutic agents trastuzumab (Carter et al, 1992) and lapatinib (Nahta et al, 2007), or current preclinical studies (Rimawi et al, 2011) and clinical trials are investigating the combination of trastuzumab plus lapatinib (Baselga et al, 2010).