ZC3H14 is a conserved CCCH-type zinc finger RNA-binding protein with primary roles in circular RNA (circRNA) biogenesis and poly(A) tail regulation. ZC3H14 binds to exon-intron boundaries and 3'-UTRs of pre-mRNAs to promote circRNA biogenesis through spliceosome association and protein dimerization 1. The protein exists as multiple nuclear and cytoplasmic isoforms generated by alternative splicing, with nuclear isoforms localizing to splicing speckles 2. Beyond circRNA regulation, ZC3H14 controls mRNA poly(A) tail length in neuronal cells and interacts with the THO complex to regulate processing of neuronal transcripts like ATP5MC1 and PSD95 3. ZC3H14 functions antagonistically to PABPN1 in nuclear RNA surveillance, controlling lncRNA turnover and export 4. Clinically, ZC3H14 mutations cause autosomal recessive intellectual developmental disorder 56, with disease mechanisms potentially involving defective axon projection and neuronal mRNA processing 5, 6. ZC3H14 acts as a tumor suppressor; its downregulation through chromosome 14 deletion promotes hepatocellular carcinoma progression 7, while CDK13-mediated ZC3H14 phosphorylation is required for nuclear RNA surveillance and its disruption drives melanoma 8. ZC3H14 is required for male fertility through circRNA-dependent spermatogenesis 1.