NDFIP1 (NEDD4 family-interacting protein 1 and NEDD4 WW domain-binding protein 5) is a 26 kDa widely expressed protein. NDFIP1 is thought to be part of a family of integral Golgi membrane proteins. It serves as an adaptor for several E3 ubiquitin ligases including NEDD4 and ITCH, and consequently modulates the stability of their targets. NDFIP1 is genetically linked to human allergic and autoimmune disease, but the cellular mechanism by which these proteins enable foreign and self-antigens to be tolerated is unresolved. Over aa10-105, human NDFIP1 is 95% identical to mouse and rat NDFIP1.