Preclinical studies in tissue culture and in xenografts using cancer cell lines with known EGFR expression have shown that EGFR overexpression itself might not be a useful predictive marker for response to EGFR targeted therapy (Sirotnak et al, 2000; Ciardiello et al, 2000, 2001; Moasser et al, 2001; Wakeling et al, 2002; Campiglio et al, 2004). The gene discussed is EGFR; the disease is cancer.