Recently, the availability of growth factors and angiogenesis have been recognized as important factors in CLL pathology [35] Our analysis of the pathways regulating cellular growth and proliferation revealed that transcripts of the 6-O endosulfatase SULF2, a novel p53-target gene [36], were differentially regulated in patients and dramatically more abundant in cells of resistant patients (Fig. 5). Here, SULF2 is linked to B-cell chronic lymphocytic leukemia.