Utilizing the sequences from the DTG mice with Id-driven lupus, we found IgVH CDR3 sequences with similarities to a histone H2A as well as H4, sequences previously identified as a Th cell antigens in lupus (13), Figure 4A. Similar matches were found for human IgVH CDR3 sequences when compared with human histone H2A and H4 (Figure S1 in Supplementary Material). The gene discussed is ID1; the disease is systemic lupus erythematosus.