Serum levels of sFASL in sensitive and refractory GVHD patients. Time course of individual sFASL levels (A) normalized to the day closest to escalation of immunosuppression (day 0) in 19 patients with therapy-sensitive (left panel) and 25 patients with refractory GVHD (right panel). (B) Absolute serum levels of sFASL in the individual sensitive (n = 19, left panel) and refractory (n = 25, right panel) GVHD patients at escalation of immunosuppression (“escalation”) and during the “follow-up” period (days 20-90 after escalating immunosuppression). Lines represent the medians. Wilcoxon signed-rank test was applied.