SMARCA4 and neoplasm: Analysis of these latter tissues showed that both, like the mammary gland, contain cells that normally express Brg1 and Wap. Thus, tumor formation in Brg1 mutant mice appears to be confined to particular cell types that require BRG1 and also express Wap. Our results now show that such cells exist both in the ovary and the uterus but not in either the luminal or the basal compartments of the mammary gland.