YAP1 and breast cancer: These observations suggest that inconsistent results reported in breast cancer cells in response to Wnt or YAP inhibition (Anastas and Moon, 2013; Green et al., 2013; Maugeri‐Saccà and De Maria, 2016) may be associated with ineffective CSC targeting due to epithelial and/or mesenchymal states, TNBC EMT/MET plasticity, and YAP and Wnt feedbacks.