CXCR4 and B-cell chronic lymphocytic leukemia: CXCR4 surface expression was also measured after 10 min incubation with 2-AG, and we concluded that 2-AG did not affect the expression of CXCR4 compared with incubation with medium alone in either disease type (p = 0.11 for MCL and p = 0.77 for CLL).