DOCK9 (Dedicator of Cytokinesis 9) is a gene that encodes a guanine nucleotide exchange factor (GEF) protein. GEFs are important regulators that activate Rho family GTPases, which control key cellular processes such as cytoskeletal organization, cell shape, and migration. DOCK9 plays a critical role in influencing cell morphology, adhesion, and movement, making it significant in developmental biology and cancer progression.