S100A12 and psoriatic arthritis: Both calprotectin and calgranulin C are well-known indicators of systemic inflammation, and their levels have been found to be elevated in the blood in patients with a diverse range of inflammatory and infectious conditions, including acute otitis media, familial Mediterranean fever, inflammatory bowel disease, Kawasaki's disease, cystic fibrosis, rheumatoid and psoriatic arthritis, tuberculosis, severe sepsis, ventilator-associated lung injury, trauma, noninfectious critical illness, and microtrauma induced by long-distance running [28–33].