Biomarkers at onset of cGVHD. (A-E) ELISA results of median plasma concentrations of CXCL9 (A), BAFF (B), CD13 (C), IL2Rα (D), and elafin (E) in the no cGVHD patients (n = 18) and refractory de novo cGVHD patients (n = 17) from the discovery cohort. (F-J) ELISA results of median plasma concentrations of CXCL9 (F), BAFF (G), CD13 (H), IL2Rα (I), and elafin (J) in the non-cGVHD patients (n = 64) and de novo cGVHD patients (n = 45) from the validation cohort. Data are illustrated as box and whisker plots with the whiskers indicating the 90th and 10th percentiles.