CDC42SE1 (CDC42 small effector 1) is a 9 kDa protein that functions as a downstream effector of the Rho GTPase CDC42, primarily regulating actin cytoskeleton organization and cell proliferation control. Mechanistically, CDC42SE1 binds CDC42 through its CRIB domain to modulate CDC42-dependent signaling pathways 1. In skin cancer cells, CDC42SE1 acts as a tumor suppressor by inhibiting the Akt/mTOR signaling pathway, with reduced CDC42SE1 expression correlating with increased cell proliferation and tumorigenesis 1. The gene has emerging disease relevance across multiple pathological contexts: it was identified as a hub gene in an immune function-associated signature for Alzheimer's disease detection, demonstrating diagnostic potential with area under the curve of 0.821 2. CDC42SE1 was also identified as a significant gene in sodium-potassium balance regulation, linking it to blood pressure control 3. Additionally, CDC42SE1 expression correlated with chemosensitivity to combined taxane and SAHA treatment in gastric cancer 4. Clinically, CDC42SE1 represents a potential biomarker for cancer progression and a therapeutic target, with its restoration potentially offering anti-tumor benefits through Akt pathway inhibition.