Interestingly, all CLL and PTCL cases presented with B220+CD19+CD5+ and CD3+CD8+ immunophenotypes, respectively, suggesting that normal B-1a B cells and cytotoxic CD8+ T cells are in particularly sensitive to cellular transformation in the absence of Dnmt3a. Here, CD5 is linked to mature T-cell and NK-cell non-Hodgkin lymphoma.