To investigate whether the dysregulated Hippo/YAP/TAZ pathway signature identified from the MCF10A model is relevant for other cancer cell lines and tumors, we performed bioinformatics analysis on the Hippo pathway activities in a broad spectrum of breast cancer cell lines in CCLE64 as well as patient tumor sample data in TCGA and METABRIC databases. This evidence concerns the gene WWTR1 and breast cancer.