YAP1 and cancer: Our experimental systems in NIH3T3 cells overexpressing YAP or mtYAP, in which the serine target of LATS1/2 was substituted with alanine, recapitulate these two cancer types in which aberrantly activated YAP is crucially involved: YAP overexpression corresponds to YAP gene amplification, while expression of mtYAP that is refractory to regulation by the Hippo pathway corresponds to Hippo pathway inactivation.