Indeed, we found that Bcl-3 depletion insome breast cancer cell lines, such as MDA-MD-231 and 4T1 cells, led tomesenchymal-to-epithelial transition (MET) induction, there was as demonstratedby reduced F-actin polarity (Supplementary Figure4d) and an obvious morph-change from fibroblast-like toround-like (Supplementary Figure 4e). Here, BCL3 is linked to breast cancer.