The main function of the immune system is to protect the body from foreign pathogens and to kill tumor cells, or “resistance” as the people call it, which consists of a variety of immune cells and the proteins they secrete. The immunoglobulins secreted by B lymphocytes and plasma cells, known as antibodies, help the body to fight against pathogens, such as antibodies to the hepatitis B virus, which protect the body from the hepatitis B virus. The body’s immunoglobulins are diverse, each targeting a variety of pathogens, each working in concert with the other to form a strong defensive bulwark. However, when B-lymphocytes or plasma cells are abnormally stimulated or become cancerous, they produce structurally identical abnormal immunoglobulins, known as monoclonal immunoglobulins, or M-proteins, a condition known medically as M-proteinemia. The main diseases that cause M proteinemia are: 1. Non-hematopoietic system diseases: often occur from chronic liver disease, nephrotic syndrome, viral infections, malignant tumors such as colon cancer, rheumatoid arthritis and other autoimmune diseases that stimulate human immune cells. The diagnosis needs to be clarified through detailed examination in hospital and timely treatment in various specialties. 2.Lymphopoietic system tumors: mainly multiple myeloma, monoclonal immunoglobulinemia of undetermined significance (MGUS), lymphoma and so on. The onset of the disease is insidious, and there may be only M proteinemia without clinical manifestations in the early stage, but gradually the symptoms of abnormal immune cells and M protein harming human body appear. Multiple myeloma mainly has symptoms such as recurrent infections, foamy urine, bone pain, fractures even without trauma, hypercalcemia, anemia, abnormal kidney function, etc. Sometimes only one of these symptoms is manifested. In the end, death usually occurs due to severe infections, multiple organ failure, or sudden death due to hypercalcemia. MGUS can be asymptomatic for a long time, but there is a possibility of transformation to hematologic malignancy, which requires long-term, professional and close follow-up in the hematology clinic to detect patients with a tendency of malignant transformation. The patients need long-term, professional and close follow-up in the hematology clinic to detect patients with a tendency of malignant transformation. Multiple myeloma and lymphoma will deteriorate rapidly and lead to death if left untreated. Therefore, early diagnosis is of great importance, and early drug treatment or bone marrow transplantation is needed to prolong the survival time and strive for survival.