The Hippo signaling pathway is an intracellular kinase cascade in which hpo kinase in complex with sav, phosphorylates wts kinase which, in turn, phosphorylates yki transcriptional co-activator leading to its cytosolic retention. Activation of the Hippo pathway results in the down-regulation of cell proliferation and up-regulation of apoptosis, limiting tissue size. (Adapted from FBrf0224870).