Next-generation sequencing of BCRs from cDNA of total PB B-cell populations from three CLL patients (two untreated and one previously treated with chlorambucil/rituximab; Supplementary Table E1, Supplementary Table E2, online only, available at www.exphem.org) yielded between 112,722 and 222,801 BCR sequences (after filtering for Ig similarity, length, and primer sequences removal according to Bashford-Rogers et al. Here, BCR is linked to B-cell chronic lymphocytic leukemia.