Anti-proliferative protein Anti-proliferative proteins have been shown to include mammalian and avian protein BTG1 (which appears to be involved in negative regulation of cell proliferation) and rat/mouse NGF-inducible protein PC3/TIS21 (BTG2) [<cite idref="PUB00001219"/>, <cite idref="PUB00001829"/>, <cite idref="PUB00004735"/>].These proteins have from 158 to 363 amino acid residues, that are highly similar and include 3 conserved cysteine residues. BTG2 seems to have asignal sequence; while the other proteins may lack such a domain. The sequenceof the N-terminal half of these proteins is well conserved.