CDC42EP2 (CDC42 effector protein 2) is a Cdc42 effector protein that functions in actin cytoskeleton organization and cell morphology regulation. Primary mechanistic studies indicate CDC42EP2 acts downstream of the small GTPase CDC42 to promote actin filament polymerization and pseudopodia formation, particularly in fibroblasts 1. The protein plays a key role in cytoskeletal remodelling and mediates cell shape changes in response to mechanical stimuli 2. CDC42EP2 expression is mechanically responsive, being upregulated during early stages of cyclic tensile stress in periodontal ligament cells and downregulated under prolonged stretch conditions 32. Beyond structural roles, CDC42EP2 emerges as a disease-relevant biomarker across multiple pathologies. It is identified as a core hub gene shared between rheumatoid arthritis and myasthenia gravis, correlating with immune cell infiltration patterns 4. CDC42EP2 participates in inflammation-hypoxia-related pathogenic mechanisms in idiopathic pulmonary fibrosis and functions in oxidative stress pathways associated with benzene-induced hematotoxicity and bone marrow failure 56. Additionally, CDC42EP2 appears in recurrent gene fusion events in gastrointestinal stromal tumors and is implicated in various rare connective tissue and neurological disorders through SOD3-correlated networks 78. These findings position CDC42EP2 as both a structural regulator of cytoskeletal dynamics and a multidisease biomarker with potential diagnostic and therapeutic significance.