H2BC21 and systemic lupus erythematosus: Importantly, the modifications we previously linked to SLE, i.e. histone H4 peptides acetylated at lysines 8, 12 and 16, H3 peptides trimethylated at lysine 27 and H2B acetylated at lysine 12 were among the prime targets for SLE autoantibodies as reported by aforementioned studies.