The neoplastic plasma cells almost always secrete a monoclonal immunoglobulin (Ig) or an Ig fragment. It can be identified by serum or urine protein electrophoresis and is known as the M component. In a normal person, the serum proteins separate into 5 major fractions (as shown in this graphic) based on their electric charge and size. These are albumin, alpha1 globulins (alpha1 anti-trypsin, alpha lipoprotein), alpha2 globulins (alpha2 macroglobulin, haptoglobin), beta1 and beta2 globulins (beta lipoprotein, complement C3), and gamma globulins (polyclonal antibodies comprising heavy chains IgG, IgA, IgM, IgD, and IgE; light chains kappa and lambda). A normal gamma zone appears as a blush or smear without any peaks or asymmetry. Image source: Simon Caulton - Own work, CC BY-SA 3.0, Original Source is here.