Taking the commonly cited cost-effectiveness threshold of the National Institute for Clinical Excellence (NICE) of £20 000 per QALY (NICE, 2004; Rawlins and Culyer, 2004) with a grey area between £20 and 40 000, there would only have to be an average gain of 0.65 (0.75) QALY per cancer detected in the BRCA1 (BRCA2) group and 1.4 QALYs for the whole group to demonstrate acceptable cost-effectiveness for CE MRI. The gene discussed is BRCA1; the disease is cancer.