Arfaptin 2, or ADP-ribosylation factor interacting protein 2, is a Rac1 binding protein necessary for Rac-mediated actin polymerization and the subsequent formation of membrane ruffles and lamellipodia.1 Arfaptin-2 has been shown to be involved in interactions between the Rac and ARF signaling pathways.2 Arfaptin 2 also regulates the aggregation of mutant Huntingtin protein by possibly impairing proteasome function. Expression of Arfaptin 2 was shown to be increased at sites of neurodegeneration. Mutant Huntingtin protein is characteristic of Huntington’s disease, an inherited neurodegenerative disorder.3