BMI1 and cancer: In conclusion, doxorubicin treatment of a heterogenous cancer cell population leads to clonal evolution and selection of miR-200c low expressing cells and subsequently to an up-regulation of various target genes including EMT inducing repressors like Zeb1 and Zeb2 [41], [49] as well as chemoresistance inducing factors like TrkB or Bmi1 resulting in enhanced survival signaling (Figure 7).