<prompt> The immunoglobulin least commonly involved in Multiple Myeloma is:IgGIgMIgAIgD  <response>: Answer is D IgD The M component in Multiple Myeloma can be made up of the immunoglobulins IgG, IgM, IgD, IgA, and IgE; light chains alone; or heavy chains alone. IgG Myeloma is the most common form of Multiple Myeloma while Ig D 2 and IgE Rare are the least common. 