The upregulation of transcripts coding for the variable domain of immunoglobulin light chains (IGLV and IGKV genes) that participate in antigen recognition were markers of subgroup II, while their downregulation were markers of subgroup I. Differential levels of IGVL and IGKV gene transcripts, as seen in subgroup I, may control self-reactivity of human antibodies27, and the reduction in the diversity of light chains has been associated with several autoimmune diseases, including systemic lupus erythematosis (SLE), type 1 diabetes, and myasthenia gravis28, 29. Here, IGLL5 is linked to autoimmune disease.