One repressor to rule them all: ANCO1 links YAP and AIB1.

The transcriptional co-activators YAP and AIB1 individually promote breast cancer progression, but are not known to be mechanistically linked. A study published in this issue of EMBO Reports [1] now shows that YAP-AIB1 form a physical complex in breast epithelial cells that cooperates in both activation and, unexpectedly, repression of key breast cancer genes. The repressive effect is due to the recruitment of ANCO1, a previously defined AIB1 interactor [2] that binds and inhibits the YAP-AIB1 complex. These data identify ANCO1 as a candidate tumor suppressor through YAP-AIB1 inhibition and could hint at a broader crosstalk between pathways that utilize YAP and AIB1 to control epithelial homeostasis.