A search of publically available breast cancer microarray data sets using Oncomine (Compendia Bioscience, Ann Arbor, MI) revealed that ARID4B expression was 2.3-fold higher in 40 ductal breast carcinoma samples compared to 7 normal breast tissue samples in the Richardson study [15], confirming that high ARID4B expression is clinically associated with breast cancer (Figure S4). The gene discussed is ARID4B; the disease is breast ductal adenocarcinoma.