By using the methodology of systematic reviews of the literature with meta-analyses, our Group has shown a prognostic role for several biological factors in lung cancer: p53 (Steels et al, 2001), Bcl-2 (Martin et al, 2003), vascular endothelial growth factor (VEGF) (Delmotte et al, 2002), epidermal growth factor receptor (EGFR) (Meert et al, 2002a), Neu (Meert et al, 2003) and microvessel density (Meert et al, 2002b). The gene discussed is EGFR; the disease is lung carcinoma.