CRIPTOP4 and B-cell chronic lymphocytic leukemia: Analyzing the contribution of CD41a and CD49e as well as of CR3 and CR4 to the adhesion to fibrinogen of malignant B cells we found, that both CR3 and CR4 were involved (Fig 3), while neither CD41a nor CD49e contributed significantly to this function of CLL B cells (S2 Fig).