YAP (Yes-associated protein) is a transcription co-activator in the Hippo tumor suppressor pathway and controls cell growth, tissue homeostasis and organ size. YAP is inhibited by the kinase Lats, which phosphorylates YAP to induce its cytoplasmic localization and proteasomal degradation. YAP induces gene expression by binding to the TEAD family transcription factors.
The function of YAP in human cancer is complex and could be cell-type-dependent. For instance, YAP could function as a tumor suppressor in some cell types, such as hematological cancers, by inducing apoptosis in response to DNA damage.