Therefore, the junctions and flanking sequences of rearrangements between the KDE and iRSS were sequenced following the cloning of PCR‐amplified iRSS to KDE rearrangements from genomic DNA extracted from CD19+ Igλ+ B cells from two healthy controls and two SLE patients with B cells expressing both light chains. This evidence concerns the gene CD19 and systemic lupus erythematosus.