The function of FGD3 (FYVE, RhoGEF and PH domain containing 3, Ensembl gene identifier ENSG00000127084) is as follows. Promotes the formation of filopodia. May activate CDC42, a member of the Ras-like family of Rho- and Rac proteins, by exchanging bound GDP for free GTP. Plays a role in regulating the actin cytoskeleton and cell shape (By similarity). .