Figure 1 DST/anti‐CD154 induces and maintains long term airway allograft tolerance. Without the use of immunosuppressants, treatment with DST/αCD154, but not either DST or anti‐CD154 alone, maintained lumen patency and prolonged tracheal allograft survival indefinitely (>100 days). The freedom from airway rejection in allografts transplanted into recipients under treatments of DST, anti‐CD154, DST/anti‐CD154, or no treatment is shown as the mean percentage of airway lumen patency (n = 5–11 and SDs ⩽18% for each treatment arm at each time point). *p<0.05 compared with control allografts at the same time point.