Marked differences in sensitivity to cetuximab were observed in colon cancer cells primed with EGF, as HT-29 cell growth was reduced by high cetuximab concentrations (10-100 μg/ml; IC50 50.12 μM), while WiDr cells were unaffected by mAb at any concentration tested (compare Figure 1B with 1E). The gene discussed is EGF; the disease is colonic neoplasm.