PFDN1 (prefoldin subunit 1) is a molecular chaperone that binds cytosolic chaperonin and facilitates protein folding of nascent polypeptides, particularly actin and tubulin monomers during cytoskeletal assembly 1. Beyond its canonical cytoplasmic chaperone function, PFDN1 localizes to the nucleus and modulates transcriptional processes, including direct interaction with the cyclin A promoter 1. The protein exhibits context-dependent cellular localization; during viral infection, PFDN1 is recruited to rabies virus nucleoprotein-containing structures 2, and it associates with centrosomes during mitosis where it regulates cytokinesis 3. Clinically, PFDN1 is significantly upregulated in multiple cancer types, including lung, gastric, and hepatocellular carcinomas, where elevated expression correlates with poor prognosis and metastatic potential 1, 4, 5. PFDN1 promotes epithelial-mesenchymal transition and cell invasion through TGF-β1/PFDN1/cyclin A and Wnt/β-catenin signaling axes 1, 4. In colorectal cancer, PFDN1 accumulation drives cytokinesis defects and aneuploidy 3. Additionally, PFDN1 expression correlates with structural brain atrophy across the Alzheimer's disease spectrum 6, and genetic variation in PFDN1 associates with migraine susceptibility and thyroid dysfunction 7.