Consistent with the ANA staining patterns, only IgM antibodies from the WT→VM chimeras, and no other groups, showed extensive autoantigen reactivity, particularly against autoantigens common to scleroderma/systemic sclerosis and SLE/Sjögren’s syndrome (Figure 5, C and D, and Supplemental Figures 5 and 6). Here, CD40LG is linked to scleroderma.