The mean relative adhesion (±SEM) of CLL cells on TNFα-treated HUVEC layer significantly decreased from 206% (±34.2%) to 118.5% (±20.5%) (n=5, p<0.05) in VLA-4 high expression group, and from 115.6% (±18.3) to 98.8% (±14.8%) in VLA-4 low expression group (n=5, p=ns). This evidence concerns the gene TNF and B-cell chronic lymphocytic leukemia.