This gene encodes a nuclear protein that belongs to a novel family of proteins required for vertebrate somitogenesis. Members of this family have a tetrapeptide WRPW motif that is required for interaction with the transcriptional repressor Groucho and a carboxy-terminal Ripply homology domain/Bowline-DSCR-Ledgerline conserved region required for transcriptional repression. Null mutant mice die soon after birth and display defects in axial skeleton segmentation due to defective somitogenesis. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Feb 2016].