PABPC4 (poly(A) binding protein cytoplasmic 4) is an RNA-binding protein that primarily functions in post-transcriptional regulation of mRNA metabolism. PABPC4 binds to poly(A) tails of mRNAs and plays crucial roles in translation regulation and mRNA stability 1. The protein demonstrates specific binding to SMIM26 mRNA, facilitating its post-transcriptional regulation and ribosomal transfer for protein translation 1. Beyond mRNA binding, PABPC4 exhibits diverse regulatory functions including interaction with nuclear receptor corepressor NCoR1, where it modulates metabolic stress responses by affecting NCoR1 ubiquitination and degradation, subsequently influencing mitochondrial function and oxidative metabolism 2. PABPC4 also functions as a host antiviral factor, broadly inhibiting coronavirus replication by targeting viral nucleocapsid proteins for degradation through selective autophagy pathways involving E3 ubiquitin ligase MARCH8 3. Clinically, PABPC4 shows significant disease relevance, with elevated expression associated with poor prognosis in prostate cancer 4 and involvement in diffuse large B-cell lymphoma progression 5. Additionally, PABPC4 has been identified as a potential therapeutic target in type 2 diabetes through its role in visceral adipose tissue metabolism 6.