As we will see later on in this review serum β2M levels also increase in solid organ malignancies, lymphoproliferative disorders such as myeloma and chronic lymphoblastic leukemia, and many autoimmune diseases such as Crohn’s disease, Sjögren’s syndrome, systemic lupus erythematosus, and rheumatoid arthritis. The gene discussed is B2M; the disease is Sjogren syndrome.