CXCR4 and B-cell chronic lymphocytic leukemia: Regarding the relationship between CXCR3 and CXCR4, correlation analysis revealed a negative correlation between percentages as well as expression (MFI) of CXCR3 with CXCR4 on CLL cells (rs = −0.35, P = 0.009 and rs = −0.38, P = 0.006, respectively) (Figure S3).