Since SWI/SNF components are frequently mutated or deleted in cancer (Oruetxebarria et al. 2004; Shain and Pollack 2013), we decided to confirm that Arid1b knockdown prevented senescence using two shRNAs targeting murine Arid1b (Fig. 1C; Supplemental Fig. S1C,D). The gene discussed is SMARCA1; the disease is cancer.