The markers identified by our review were eosinophilia (4 studies, 805 patients), serum amyloid A protein (1 study, 12 patients), nitric oxide (1 study, 50 patients), alpha-glutathione S-transferase (2 studies, 67 patients), pi-glutathione S-transferase (1 study, 44 patients), peripheral T-cells and soluble IL-2 receptor (1 study, 119 patients), guanylate-binding protein 2 mRNA (1 study, 46 patients), graft-derived cell-free DNA (1 study, 115 patients), procalcitonin (1 study, 20 patients), and serum HLA class I soluble antigens (1 study, 14 patients). The gene discussed is HPGDS; the disease is Increased total eosinophil count.