A kinase cascade by four tumor suppressors constitutes the core of the Hippo pathway, comprising two signaling complexes—the Hpo-Sav (MST-SAV in mammals) and the Wts-Mat (LATS-MOB in mammals), which govern the cellular localization, activity, and fate of signaling effectors YAP and TAZ (1, 5–8). The gene discussed is YAP1; the disease is neoplasm.