We found that collectively a subset of unmodified and post-translationally acetylated histone peptides in combination with several whole antigens (dsDNA, U1–70, H2B and H3) could be used to profile serum antibodies and differentiate SLE patients from healthy individuals (Figure 4D) with higher accuracy than antibody profiling with peptides alone (Figure 4B) or whole antigens alone (Figure 4C). This evidence concerns the gene H2BC21 and systemic lupus erythematosus.