A cost-effectiveness analysis of the UK Magnetic Resonance Imaging for Breast Screening (MARIBS) study evaluated the incremental cost per cancer detected by XRM and XRM plus MRI, and concluded that adding MRI to XRM is potentially cost-effective for women at high familial risk of breast cancer, particularly for BRCA1 and BRCA2 mutation carriers (Griebsch et al, 2006). The gene discussed is BRCA1; the disease is breast cancer.