For instance, the absence of certain ATP-dependent chromatin remodeling factors of the SWI/SNF complex affects mammary gland development (Cohet et al., 2010; Skibinski et al., 2014), which has helped clarify the specific roles of these factors in breast cancer development and resistance to therapy (García-Pedrero et al., 2006; Nagarajan et al., 2020; Xu et al., 2020). The gene discussed is SMARCA1; the disease is breast cancer.