CRNN is a member of the "fused gene" family of proteins, which contain N-terminus EF-hand domains and multiple tandem peptide repeats. It contains two EF-hand Ca2+ binding domains in its N-terminus and two glutamine- and threonine-rich 60 amino acid repeats in its C-terminus. This protein, also known as Survival factor that participates in the clonogenicity of squamous esophageal epithelium cell lines, attenuates deoxycholic acid (DCA)-induced apoptotic cell death and release of calcium. When overexpressed in oral squamous carcinom cell lines, regulates negatively cell proliferation by the induction of G1 arrest. Recombinant CRNN protein was expressed in E. coli.