Given that HMGB1, an alarmin that activates the innate immune system [31], has been recently identified in large amounts on NETs from patients with pediatric SLE [27], its localization on extracellular DNA web-like formations, assessed by staining with DAPI, released by synovial fluid PMNs from patients with acute gout was investigated. This evidence concerns the gene HMGB1 and systemic lupus erythematosus.