A group of related diseases characterized by an unbalanced or disproportionate proliferation of immunoglobulin-producing cells, usually from a single clone. These cells frequently secrete a structurally homogeneous immunoglobulin (M-component) and/or an abnormal immunoglobulin.
Note: Use of the qualifier "multiple interactions" designates that the annotated interaction
is comprised of a complex set of reactions and/or regulatory events, possibly involving
additional chemicals and/or gene products.