ARHGAP17 is a Rho GTPase-activating protein that functions as a multifaceted regulator of cellular processes through inactivation of small GTPases, particularly Cdc42 and Rac1. Mechanistically, ARHGAP17 catalyzes conversion of active GTP-bound GTPases to inactive GDP-bound states, thereby regulating actin cytoskeleton organization and cell polarity 1. In epithelial tissues, ARHGAP17 maintains tight junction integrity and apical polarity by controlling Cdc42 activity 2, with spatial localization to invadopodia controlling coordinated GTPase activation and inactivation cycles during invadopodia turnover 1. Cerebellar development requires ARHGAP17 function, as Wdr4-mediated degradation of ARHGAP17 promotes granule neuron progenitor proliferation via Rac1 activation 3. ARHGAP17 emerges as a tumor suppressor across multiple cancer types. In cervical cancer, reduced ARHGAP17 expression enhances proliferation through PI3K/AKT pathway activation 4. In chemoresistant colon cancer, ARHGAP17 overexpression sensitizes cells to 5-fluorouracil-induced apoptosis by suppressing Rac1 5. Similarly, in hepatocellular carcinoma, ARHGAP17 inhibits progression by inactivating Wnt/β-catenin signaling 6. Under mechanical stress, ARHGAP17 protects periodontal ligament fibroblasts from apoptosis via Rac1/Cdc42 inactivation 7. Clinically, reduced ARHGAP17 expression correlates with poor cancer prognosis, suggesting therapeutic potential for ARHGAP17 restoration in oncology.