what is plasma cell monoclonal gammopathy
Monoclonal gammopathy of undetermined significance (MGUS) Overview. Monoclonal gammopathy of undetermined significance (MGUS) is a condition in which an abnormal protein â known as monoclonal protein or M protein â is in your blood. The protein is produced in a type of white blood cell (plasma cells) in your bone marrow. MGUS usually causes no problems.