Also, regarding the activity, we observed a different RR according to third-line regimen and primary tumor site: in particular, in the L-sided tumor group, RR was 43% in patients treated with anti-EGFR and 0% in patients treated with R/T (p <0.0001), while no difference was observed in the R-sided tumor group. The gene discussed is EGFR; the disease is neoplasm.