ARHGAP26 (Rho GTPase activating protein 26) functions as a negative regulator of Rho family GTPases, particularly RhoA and Cdc42, by promoting their hydrolytic conversion to inactive GDP-bound forms 1. The protein plays diverse cellular roles including regulation of mitochondrial homeostasis, where it serves as a PINK1 substrate coordinating cytoskeletal and metabolic remodeling to promote cardioprotection through mitophagy 2. ARHGAP26 is essential for oocyte quality control, maintaining mitochondrial integrity through interaction with Cofilin1 to regulate Drp1 dynamics, and preventing aneuploidy that leads to embryonic development defects 3. The gene's expression is regulated by ADAR1-mediated RNA editing, which disrupts miR-30b-3p and miR-573 binding sites, ultimately controlling RhoA activity 1. Disease associations include recurrent fusion events in gastric cancer, particularly the CLDN18-ARHGAP26 fusion in diffuse gastric cancer, which paradoxically promotes RHOA activation and drives oncogenic FAK and YAP-TEAD signaling 4. ARHGAP26 deficiency has been linked to patent ductus arteriosus through RhoA-ROCK-PTEN pathway activation 5 and identified in patients with recurrent pregnancy loss 3, highlighting its clinical significance across multiple organ systems.