CD40 and idiopathic pulmonary fibrosis: In end-stage IPF, the activation score (CD40+) was higher than in early IPF and smoking controls [73 (9–92) vs. 33 (0–90)%; p = 0.005 vs. 23 (0–75); p = 0.002], which suggests a possible role of TLS activation in the deterioration of pathology.