As shown in Fig. 1A, the expression of C5aR remained steady in healthy controls and non-GVHD patients who had undergone HSCT; however, C5aR was up-regulated on the monocytes in cGVHD patients and had significantly higher levels than those from healthy controls as well as non-GVHD patients. The gene discussed is C5AR1; the disease is graft versus host disease.