A new gene, which cross-hybridized with a rat PCNA cDNA probe, has been isolated from a human genomic cosmid library. A comparison of the gene with the human PCNA cDNA revealed 71% homology for the nucleotide sequences. This gene completely lacks introns and has traces of a polyA tail which the messenger RNA of the active gene retains. These facts indicate that this gene was generated by the reverse-transcription of a processed RNA for PCNA and exists as a PCNA pseudogene in the human genome.