ABI2 is a multifunctional adaptor protein that regulates actin cytoskeleton dynamics critical for cell motility and morphogenesis. As a core component of the WAVE regulatory complex, ABI2 activates Arp2/3-mediated actin nucleation to promote lamellipodia formation and cell protrusion 12. ABI2 acts as both regulator and substrate of ABL tyrosine kinases and interacts with Rac GTPase signaling 3. In normal physiology, ABI2 controls dendritic spine morphogenesis, regulates adherens junction assembly in epithelial cells, and is essential for lens morphogenesis 4. ABI2-deficient mice exhibit defective cell migration, abnormal dendritic spine structure, and severe cognitive deficits, highlighting its role in neuronal connectivity and learning 4. Clinically, ABI2 exhibits complex disease associations. In hepatocellular carcinoma, ABI2 is upregulated and promotes cancer stem cell properties and tumor recurrence through the MEOX2/KLF4-NANOG axis and HHEX-mediated pathways 56. In prostate cancer, PIM1-mediated phosphorylation of ABI2 at Ser183 enhances actin dynamics and hypoxia-induced tumor invasion 2. Conversely, ABI2 downregulation by EBV-miR-BART13-3p drives epithelial-mesenchymal transition in nasopharyngeal carcinoma 7, suggesting context-dependent oncogenic versus tumor-suppressive roles. ABI2 expression associates with renal cell carcinoma grade and platelet/lymphocyte ratio 8.