Mitochondrial tumor suppressor 1 is a protein which contains a C-terminal domain able to interact with the angiotension II (AT2) receptor and a large coiled-coil region allowing dimerization. Multiple alternatively spliced transcript variants encoding different isoforms have been found for this gene. One of the transcript variants has been shown to encode a mitochondrial protein that acts as a tumor suppressor and participates in AT2 signaling pathways. Other variants may encode nuclear or transmembrane proteins but it has not been determined whether they also participate in AT2 signaling pathways.Ubiquitously expressed (at protein level). Highly expressed in brain. Down-regulated in ovarian carcinoma, pancreas carcinoma, colon carcinoma and head and neck squamous cell carcinoma (HNSCC).