Preclinical studies in breast cancer cell lines that overexpress HER2 show that combined EGFR and HER2 inhibition may be more effective than treatment with single agents, regardless of EGFR expression level (Moasser et al, 2001; Moulder et al, 2001; Normanno et al, 2002; Anido et al, 2003). Here, ERBB2 is linked to breast carcinoma.