As shown in the example in Fig. 4b, patient PBMC that were collected 6 months following HSCT were co-cultured with CD40L-Tri-activated autologous CLL cells, and then purified CD8 T cells were restimulated in an IFNγ-ELISPOT assay with autologous CLL cells activated by CD40L-Tri, NIH3T3/tCD40L, or shrtCD40L, or by PHA. This evidence concerns the gene CD8A and B-cell chronic lymphocytic leukemia.