Septin-9 is a member of the septin family, which contains cytoplasmic cytoskeletal filament-forming proteins that have a conserved GTP-binding domain.Septin-9 is a member of the septin family, which contains cytoplasmic cytoskeletal filament-forming proteins that have a conserved GTP-binding domain (Osaka et al., 1999 [PubMed 10339604]).[supplied by OMIM]. Publication Note: This RefSeq record includes a subset of the publications that are available for this gene. Please see the Entrez Gene record to access additional publications.