CXCL10 and Buschke-Ollendorff syndrome: Nominal logistic regression of cfDNA, CXCL10, and the interaction of cfDNA and CXCL10 could distinguish BOS, RAS, and stable phenotypes from one another with a ROC AUC of 0.8571, 0.8500, and 0.8679 respectively (p = 0.0004) (Figure 2a).