However, a bone marrow biopsy, when available, should be performed as the finding of hemophagocytosis in the bone marrow may help to justify the choice of therapeutic options as sCD25, which serves as a marker of T cell activation, and sCD163, as a marker of hemophagocytosis, is specific for the occurrence of HLH.[4]. The gene discussed is CD163; the disease is hemophagocytic syndrome.