In another study, formylated peptides that were produced by wild-type strain of S. aureus were capable of inducing S. aureus septic arthritis [48] and a bacterial plasmid-encoded peptide from S. aureus was sufficient of causing MPO-ANCA glomerulonephritis in mice [49], illustrating the potency also of bacterial-derived fMET in causing disease. The gene discussed is MPO; the disease is bacterial arthritis.