The capability of CC and CXC chemokines to stimulate functional properties through the evaluation of cytosolic Ca²⁺ level shows a consistent mobilization of Ca²⁺ in the presence of some chemokines. The effect of several chemokines on cytosolic Ca²⁺ concentration in malignant B cells obtained from 2 representative NHL patients and in normal B lymphocytes obtained from a healthy subject. The assay was performed in incubation medium containing 1 mM CaCl₂. A discrete Ca²⁺ increase was observed following crosslinking surface membrane immunoglobulins (at a concentration of 500 ng/mL), as a positive control. Where indicated by arrows, the chemokines were added at a concentration of 100 ng/mL. At the end of each experiment 2 mM EGTA (ethylene glycol tetraacetic acid) was added and successively the Ca²⁺ ionophore ionomycin (1 μM) was added to induce a massive [Ca²⁺]_i increase. The values are expressed as ratio between the intensity of the fluorescence signal obtained by exciting cells alternatively at 340 and 380 nm. An increase in ratio reflects an increase in [Ca²⁺]_i.