In order to test the role of RBM47 as a suppressor of breast cancer progression, we stably introduced both wild type RBM47 and RBM47I281fs in the lung metastatic (LM2) and brain metastatic (BrM2) derivatives of the MDA-MB-231 triple negative breast cancer cells (MDA231 for short), respectively (Figure 2—figure supplement 1A; Minn et al., 2005; Bos et al., 2009). Here, RBM47 is linked to breast cancer.