Figure 1.

Proposed model of second malignancies after multiple myeloma. Examples for the categories include the following: (1) alkylating agents, immunomodulatory agents, autologous stem cell transplant, and radiation; (2) molecular subtypes of disease, biclonal disease, and bone marrow microenvironment; (3) polymorphisms in germline genes (eg, drug-metabolizing genes, erythropoietin promoter gene), chronic antigenic stimulation, and genetic susceptibility with other malignancies; (4) occupation, pesticides, and chlorinated solvents; and (5) tobacco, obesity, alcohol, and diet.