VPREB1 and neoplasm: Transcript abundance of Rad51 (encoding a common DNA damage response factor) was also significantly reduced in both tumor and unaffected EB cells compared to wild-type and Bcl-xLTg pre-B cells, in accordance with previous findings that Ebf1 heterozygosity results in decreased expression of this gene and increased DNA damage in pro-B cells.23 Transcripts of the EBF1 target genes VpreB, Rag1, and Cd79a/mb-1 were also significantly reduced in tumor cells compared to unaffected EB cells, likely as a result of reduced EBF1 activity.