YAP1 and neoplasm: The hydrodynamic tail vein injection/Sleeping Beauty transposon model, particularly with coactivation of CTNNB1 and Yap-1, has been used successfully to reveal genes and pathways that contribute to disease, but the tumors generated in animals tend to be initially small, multifocal nodules that eventually replace the entire organ with tumor, which may make quantifying tumor burden difficult.