When directly compared with RA NETs, the levels of MPO, leukocyte elastase inhibitor and thymidine phosphorylase were higher in SLE NOX2-dependent NETs, whereas histones H1.0, H2B (type 1-J), H2B (type 2-F), and H4 were higher in SLE NOX2-independent NETs (128). Here, MPO is linked to systemic lupus erythematosus.