encodes a nuclear protein expressed in a variety of tissues. The rat homolog, Rp8, is transiently expressed in immature thymocytes and is thought to be involved in programmed cell death. Expression of the human gene has been shown to be repressed by BCL6, a transcriptional repressor required for lymph node germinal center development, suggesting that BCL6 regulates apoptosis by its effects on PDCD2. This gene is closely linked on chromosome 6 to the gene for TBP, the TATA binding protein. Two transcripts encoding different proteins have been identified. PDCD2, contained an open reading frame of 1,032 bp encoding 344 amino acids; it showed 81% identity in DNA sequence and 83% identity in amino acid sequence to rat Rp8. The PDCD2 gene was expressed in all human tissues examined.