First identified by comparing gene expression in malignant vs. benign B-cells, BLR1 (Burkitt's Lymphoma Receptor 1) mRNA was detected in Burkitt's lymphoma cell lines and lymphatic tissue but not in undifferentiated B-lymphocytes or hematopoietic cells of myeloid, monocytic, erythroid, or T-lymphocytic origin (24). This evidence concerns the gene CXCR5 and Burkitt lymphoma.