Contrary to the tumor suppressive role of the SWI/SNF complex, the ATPase subunits of the SWI/SNF complex, BRM and BRG1, are highly expressed in primary breast cancer compared to normal breast tissue and are vital for cell proliferation (Table 1) (Bai et al., 2013; Wu et al., 2015). Here, SMARCA4 is linked to breast cancer.