Costs listed in Supplementary Table 1 are drug acquisition costs and do not include costs of outpatient visits, hospitalisation, treatment of side effects, etc. A potential benefit of targeted approaches using biological-based therapy is the avoidance or lessening of adverse effects; e.g. adverse effects resulting from EGFR-targeted therapy are relatively mild (e.g. skin rash) [16] in comparison to those observed with 5-FU (myelosuppression and gastrointestinal toxicity) [17]. The gene discussed is EGFR; the disease is exanthem.