While the highest levels of MTSS1 were found in hairy cell and mantle cell lymphomas (Fig. 5c), expression of MTSS1 was also increased in CLL as compared to normal B cells and highest among different types of leukaemia, with the fold changes from normal peripheral blood mononuclear cells (PBMCs) ranging from 1.3–3.8 for different microarray probe sets (Fig. 5c,d). This evidence concerns the gene MTSS1 and B-cell chronic lymphocytic leukemia.