Monoclonal gammopathy of undetermined significance (MGUS) and smoldering myeloma are precursor forms of multiple myeloma.
Mergæxli þróast út frá einkennalausri góðkynja einstofna mótefna-hækkun í blóði (monoclonal gammopathy of undetermined significance (MGUS)) og mallandi mergæxli (smoldering myeloma).