ARHGAP9 (Rho GTPase Activating Protein 9) is a gene that encodes a protein involved in regulating Rho family GTPases—molecules that control cell shape, movement, and structure. By modulating these signaling pathways, ARHGAP9 plays a role in cell migration, adhesion, and growth. It has been studied in cancer research for its potential influence on tumor cell invasion and metastasis.