To ask whether the reduced frequency of rearrangement of the KDE to the iRSS observed in SLE compared to healthy donors was due to more frequent KDE rearrangement to IgκV segments rather than the iRSS, qRT‐PCR primers were designed to target the IgκJ‐IgκC intron, 5’ of the iRSS in the same genomic DNA samples from which iRSS‐KDE rearrangement frequency had been determined (Fig. 5D). This evidence concerns the gene IGKC and systemic lupus erythematosus.