Analyses of serum samples from the individuals with known outcomes showed that higher levels of IgG3 (Figure 5A) and a higher proportion of IgG3 (as %IgG; Figure 5B) in serum close to CIS diagnosis were inversely correlated with the number of days to conversion from CIS to MS (Figure 5). The gene discussed is IGHG3; the disease is myeloid sarcoma.