Schematic diagram of Ig light chain protein expression and Ig light chain gene rearrangements according to the ordered model.

Ig light chain gene rearrangements start with rearrangement of 1IGK allele (R/G) → further IGK gene rearrangements (R/R) → 1 IGK allele deleted (D/R) and occasionally 1 IGL allele rearranged (R/G) → bothIGK alleles deleted (D/D) and 1 or 2 IGLrearrangements (R/G or R/R). Because the ordered rearrangement process is not fully strict, IGK andIGL rearrangements might coexist (in 6% of Igκ⁺ cases and in 12% of Igλ⁺ cases of the presented CBL series). G indicates germline; R, rearrangement; D, deletion.