Tracing the development of premalignancy and evolution of multiple myeloma is facilitated by detection of clonotypic M protein, a monoclonal Ig detected in blood and marker of the premalignant monoclonal gammopathy of undetermined significance (MGUS), smoldering multiple myeloma (SMM) (17) and ultimately multiple myeloma. The gene discussed is MYOM2; the disease is plasma cell myeloma.