An exome sequencing study60 of 100 breast cancers at the Wellcome Trust Sanger Institute (Cambridge, UK) identified more than 40 driver mutations in a breast cancer cohort, including genes now known to be important therapeutic targets, such as AKT1/2, ARID1B, CASP8 and MAP3K1. The gene discussed is ARID1B; the disease is breast carcinoma.