A previous study reported that TAZ served as a HIF-1 co-activator in breast cancer cells selected for metastasis to bone [18], whereas our study expands this co-activator function to MDA-MB-231 breast cancer cells, which metastasize to lungs and lymph nodes, as well as non-metastatic MCF-7 cells. Here, WWTR1 is linked to breast carcinoma.