YAP1 and breast cancer: YAP activation is essential for β-catenin function in a variety of cancers including melanoma, hepatoblastoma, colon cancer, and breast cancer, and a screen of 85 cancer cell lines determined that those driven by β-catenin were dependent on YAP (Rosenbluh et al., 2012; Tao et al., 2014; Liu et al., 2019; Quinn et al., 2021).