High expression levels of CXCR5 particularly in FL, CLL, and MCL cells were confirmed by a gene expression database analysis containing 630 cancer categories (HS_AFFY_U133PLUS_2.0; cancer entities with highest CXCR5 expression levels are shown in Supplementary Fig. 3)28. Here, CXCR5 is linked to B-cell chronic lymphocytic leukemia.