Immunoglobulin Lambda-Like Polypeptide 1 （IGLL1） is one of the substitute light chain subunits and is a part of the immunoglobulin gene superfamily which does not undergo rearrangement. Two transcript variants encoding diverse isoforms have been found for IGLL1. Mutations in IGLL1 can bring about B cell deficiency and agammaglobulinemia， an autosomal recessive disease in which few or no gamma globulins or antibodies are made.
