(A) Blocking of adhesion of B-CLL cells to stromal cells. Leukemic cells were preincubated for 1 hour with blocking antibodies before plating on stromal cells. Each bar represents the mean of adhesion inhibition of eight experiments. (B) Blocking of B-CLL cell adhesion to stromal cells untreated or treated with anti-CD54 and/or anti-CD106. B-CLL cells were simultaneously preincubated with antibodies to CD11a/CD18 or CD49d.