– Immunoglobulin lambda constant region is constant region of immunoglobulin light chains. Immunoglobulins, also known as antibodies, are membrane-bound or secreted glycoproteins produced by B lymphocytes. In the recognition phase of humoral immunity, the membrane-bound immunoglobulins serve as receptors which, upon binding of a specific antigen, trigger the clonal expansion and differentiation of B lymphocytes into immunoglobulins-secreting plasma cells. IGLC2 is 105 amino acids (aa) in length. It contains one Ig-like domain (aa 7-100) and generates a disulfide bond with an IgH chain via Cys104.