TBC1D22A is a GTPase-activating protein (GAP) that regulates Rab family GTPases, primarily involved in vesicular trafficking and cellular signaling pathways 1. The protein localizes to the Golgi apparatus and interacts with ACBD3, a key Golgi adaptor protein, competing with phosphatidylinositol 4-kinase for binding sites 2. TBC1D22A participates in tight junction and epithelial adherens junction signaling, with evidence suggesting roles in GTPase-mediated signal transduction 3. In cancer biology, TBC1D22A expression is elevated in ovarian serous cystadenocarcinoma and independently predicts poor overall survival, progression-free survival, and disease-free survival 1. High TBC1D22A expression correlates with increased M2 macrophage infiltration, elevated immune checkpoint expression, and reduced chemosensitivity to cisplatin and paclitaxel 1. Similarly, TBC1D22A was identified as a poor prognostic gene in cisplatin-resistant ovarian cancer 4. Beyond oncology, TBC1D22A is implicated in neurodevelopmental disorders. A 3 Mb genomic region containing TBC1D22A on chromosome 22.31 associates significantly with seizure prevalence in Phelan-McDermid syndrome 5, and the gene is a candidate contributor to PMS phenotypes 6. Additionally, TBC1D22A variants appear involved in monozygotic twinning through GTPase-mediated pathways 3.