In fact, significantly greater overlap between the CD5high and CD5low CLL BCRs was observed than would be expected if the CD5 state switch occurred only from cells expressing the central CD5high CLL BCR or vice versa (hypergeometric test p < 10−10; Supplementary Table E7, online only, available from www.exphem.org). This evidence concerns the gene CD5 and B-cell chronic lymphocytic leukemia.