PFDN4 (prefoldin subunit 4) is a component of the prefoldin complex that functions as a molecular chaperone, binding to nascent polypeptide chains and facilitating their transfer to cytosolic chaperonin for proper protein folding [UniProt]. The protein plays dual roles in cellular processes: as a co-chaperone involved in cytoskeletal rearrangement and as a transcriptional factor regulating cell cycle progression 12. PFDN4 demonstrates significant disease relevance across multiple cancer types. In hepatocellular carcinoma, PFDN4 is overexpressed and promotes tumor progression through activation of the MAPK/ERK signaling pathway, enhancing cell proliferation, migration, and invasion 3. The protein serves as an independent prognostic marker, with high expression correlating with poor overall survival in gastric cancer, colorectal cancer, and hepatocellular carcinoma 145. Interestingly, in colorectal cancer, some studies report that high PFDN4 expression is associated with better prognosis, with knockdown experiments showing increased cell growth and invasiveness 2. PFDN4 also participates in hepatic fibrosis development through PI3K/AKT pathway regulation and undergoes proteasome-mediated remodeling during sperm capacitation 67. These findings highlight PFDN4's potential as both a diagnostic biomarker and therapeutic target across various pathological conditions.