Similar to previous reports6,7, methylation of RASSF1A and RASD1 were absent in normal controls, including CD138-sorted normal bone marrow plasma cells (n = 8) and normal peripheral blood buffy coats (n = 10) (Supplementary Fig. S2), but detected in six (60%) and one (10%) human myeloma cell lines respectively, hence tumour-specific (Fig. 2A). The gene discussed is RASD1; the disease is plasma cell myeloma.