MMP9 and temporal arteritis: Indeed, levels of macrophage products such as soluble CD163, YKL-40, Angiopoietin-2 (Angpt-2), IL-33, VEGF, MMP-9, calprotectin and osteopontin were found elevated in the serum of GCA patients compared to healthy donors [51,104,105,106,107,108,109,110,111,112] (Figure 3).