The transcriptional co‐factors Yes‐associated protein (YAP) and transcriptional co‐activator with PDZ‐binding motif (TAZ), the main effectors of the Hippo signal transduction pathway, are emerging as pivotal determinants of malignancy in human cancer (Harvey et al., 2013; Zanconato et al., 2016a, 2016b). The gene discussed is YAP1; the disease is cancer.