 EL625 is a 20-mer antisense molecule which binds to a coding region of exon 10 in p53 RNA transcripts. It can bind to both mutant and wild type p53. p53 is involved in regulating apoptosis and DNA repair in cells. When genetic damage occurs p53 is upregulated. As the expression of p53 increases in normal cells they are more likely to undergo apoptosis rather than cell cycle arrest and DNA repair. However in malignant cells, for a given level of DNA damage they are more likely to undergo cell cycle arrest and repair rather than apoptosis. Because EL625 is theorized to increase response to chemotherapy, we propose adding EL625 to a combination of fludarabine, cyclophosphamide and rituximab. 