The majority of T-cell subsets observed in patients could be detected in CLL xenografts in similar proportions, except for significantly (P≤0.05) elevated levels of T-regulatory cells (CD4+CD25+FoxP3+), typically associated with CLL progression (Jadidi-Niaragh et al., 2013) (Fig. 3A,B). This evidence concerns the gene CD4 and B-cell chronic lymphocytic leukemia.