ARPC1A is a component of the Arp2/3 complex, a multi-subunit machine that nucleates branched actin networks in collaboration with nucleation-promoting factors 1. The complex regulates actin polymerization and cytoskeleton organization, with ARPC1A functioning as a core structural subunit 1. In normal physiology, ARPC1A participates in cortical actin dynamics and cellular processes requiring controlled actin architecture. Mechanistically, ARPC1A-containing Arp2/3 iso-complexes mediate both linear and branched actin filament formation; however, inhibitor sensitivity depends on iso-complex composition, with ArpC1A-containing complexes showing distinct pharmacological profiles compared to ArpC1B variants 1. In cancer contexts, EML4 modulates cytoskeleton dynamics by interacting with ARPC1A to enhance lamellipodia formation and cellular motility 2. Clinically, ARPC1A is significantly upregulated across multiple cancer types and correlates with poor prognosis 3. In prostate cancer, STAT3 transcriptionally upregulates ARPC1A to inhibit ferroptosis and promote progression 4. In low-grade glioma, ARPC1A represents an independent prognostic risk factor, controlling proliferation through MAPK signaling 5. In lung cancer, ARPC1A promotes malignant phenotypes through c-Myc regulation and contributes to chemotherapy resistance 3. These findings position ARPC1A as a pan-cancer biomarker and potential therapeutic target for metastasis prevention and cancer management.