CXC receptors were functionally investigated in chemotactic assay and were observed to display chemotaxis in some patients with NHL following binding to relative chemokines. Chemotactic activity of CXC chemokines (CXCL12: SDF-1α at 100 ng/mL, SDF-1β at 100 ng/mL, CXCL13 at 1 ng/mL) was tested on normal B cells obtained from 3 healthy subjects and on malignant B lymphocytes obtained from 18 patients with NHL. The concentrations were chosen in relation to a dose-response curve (see “Patients, materials, and methods”). The assay was performed in triplicate.