YAP1 and breast cancer: On the contrary, abundant literature suggested that YAP1 is a tumor suppressor gene and nuclear expression is reduced in different cancers, such as breast cancer (Matallanas et al., 2007; Yu et al., 2013; Yuan et al., 2008), head and neck cancers (Ehsanian et al., 2010), hematological cancers (Cottini et al., 2014), and CRC (Levy et al., 2007).