The expression mRNA levels for CCR9 in other leukemias, lymphomas or myelomas is much lower, although about 30% of the tumor samples in Splenic marginal zone lymphoma and about 20% of the samples in Hairy cell leukemia, Mantle cell lymphoma or Hodgkin lymphoma express high levels of CCR9 mRNA (see Figure 1A). This evidence concerns the gene CCR9 and marginal zone lymphoma.