We have previously shown9 that (i) the immunization of BALB/c mice with the pyrrolated self-molecule accelerates the production of anti-DNA Abs, (ii) a spontaneous age-dependent increase in the IgG and IgM titers to DNA/pyrP is observed in the SLE-prone MRL-lpr mice, and (iii) SLE patients exhibit prominent increases in the Ab titers against both DNA and pyrP. Here, CD40LG is linked to systemic lupus erythematosus.