Plays a key role in the Hippo/SWH (Sav/Wts/Hpo) signaling pathway, a signaling pathway that plays a pivotal role in organ size control and tumor suppression by restricting proliferation and promoting apoptosis. The core of this pathway is composed of a kinase cascade wherein Hippo (Hpo), in complex with its regulatory protein Salvador (Sav), phosphorylates and activates Warts (Wts) in complex with its regulatory protein Mats, which in turn phosphorylates and inactivates the Yorkie (Yki) oncoprotein. The Hippo/SWH signaling pathway inhibits the activity of the transcriptional complex formed by Scalloped (sd) and Yki and the target genes of this pathway include cyclin-E (cycE), diap1 and bantam. Required for cell cycle exit in eye imaginal disk and hid-induced apoptotic cell deaths that are part of normal retinal development. Activation of Drice in eye imaginal disk by either Hid or Rpr is almost completely blocked by Sav expression. Interacts with Wts via its WW domains. Interacts (via FBM motif) with Mer (via FERM domain). Interacts with Kibra. Interacts with Hpo (via SARAH domain). Interacts with jub. Third instar larvae eye disk, expressed in a stripe in the morphogenetic furrow, decreases in the region of the second mitotic wave (SMW) and increases once again posterior to the SMW. Phosphorylated by Hpo.