Source:http://linkedlifedata.com/resource/umls/id/C0021034
NCI: A protein complex that consists of two heavy chains (gamma, alpha, delta, epsilon or mu). The larger of the two immunoglobulin chain types determines the immunoglobulin class (G, A, D, E or M, respectively). The heavy chain molecules exhibit the same structure and composition, which consists of constant, variable, and hypervariable regions.,MSH: The largest of polypeptide chains comprising immunoglobulins. They contain 450 to 600 amino acid residues per chain, and have molecular weights of 51-72 kDa.