ERBB2 and breast cancer: Several randomised trials have proved the efficacy of trastuzumab in metastatic (Slamon et al, 2001; Marty et al, 2005) and adjuvant (Piccart-Gebhart et al, 2005; Romond et al, 2005; Joensuu et al, 2006; Smith et al, 2007) settings for HER-2-positive breast cancer in terms of response rate, recurrence rate and a decrease in mortality.