This review focuses on the molecular mechanisms underlying the interplay between Hippo/YAP and pivotal signaling pathways such as nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), wingless-type (Wnt)/β-catenin signaling pathway, transforming growth factor-beta (TGF-β), Hedgehog, Notch and other signaling pathways, as well as their implications in cancer biology. Here, YAP1 is linked to cancer.