YAP1 and cancer: In contrast, zonula occludens (ZO)-1 and ZO-2, which are lining proteins in tight junctions, activate yes-associated protein (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ) by inhibiting the Hippo signaling pathway [25, 26], promoting cancer cell growth and epithelial-mesenchymal transition (EMT) to enhance cancer metastasis [27–29].