Soluble CD163 is derived from the cleavage of the CD163 macrophage receptor by metalloproteinase and is released into inflammatory tissue, blood, urine, cerebrospinal fluid, and synovial fluid (6) during systemic inflammatory responses such as sepsis, liver disease, malaria, autoimmune disorders, and reactive hemophagocytic syndrome (7). The gene discussed is CD163; the disease is secondary hemophagocytic lymphohistiocytosis.