ONC‐212 treatment (2 μM for 24 hours) of primary CLL cells resulted in a significant (P < .01) down‐regulation of expression of the chemokine receptor CXCR4 and integrin CD49d, relative to cells cultured in medium alone (Figure 2C, left). This evidence concerns the gene CXCR4 and B-cell chronic lymphocytic leukemia.