MUC1 and bacterial pneumonia: Again, SFN was the biomarker showing the strongest performance for discriminating between the acute phase of the DAD group and patients with fungal/bacterial pneumonia (0.98 [0.95–1.0]); the performance of SFN was superior to those of SP-D (0.87 [0.76–0.98]) and KL-6 (0.86 [0.74–0.98]) (Fig. 3d).