CCND1 and breast cancer: Our results that MTF2 represses CCND1 expression in MDA-MB-231 (Figure 6E) may help explain the recent reports that low MTF2 expression leads to increased chemotherapeutic resistance in leukemia (Maganti et al., 2018) and downregulation of MTF2 was correlated with poorer clinical outcomes in breast cancer (Liang et al., 2018).