text: The kappa and lambda light chains undergo rearrangements of the V and J gene segments.  In this process, a functional Vlambda can combine with four functional Jλ –Cλ combinations. On the other hands, Vk gene segments can join with either one of the Jk functional gene segments. The overall rearrangements result in a gene segment order from 5 prime to 3 prime end. These are a short leader (L) exon, a noncoding sequence (intron), a joined VJ segment, a second intron, and the constant region.  There is a promoter upstream from each leader gene segment. The leader exon is important in the transcription of light chain by the RNA polymerase. To remain with coding sequence only, the introns are removed during RNA- processing and repairing. In summary,