YAP1 and breast cancer: YAP1 has been confirmed to be overexpressed in a variety of tumors, including gastric tumors (An et al., 2020), liver tumors (Bisso et al., 2020), ovarian cancer (Munoz-Galvan et al., 2020), and breast cancer (Song et al., 2018), suggesting that YAP1 has a role as a candidate oncogene in tumorigenesis.