Angiogenesis index in examined groups after injection of MNC, pre-incubated in sera from extrinsic allergic alveolitis (EAA; n = 29, Wegener's granulomatosis (WG; n = 14), collagen vascular diseases (CVD; n = 16), sarcoidosis (SAR; 83), idiopathic pulmonary fibrosis (IPF; n = 31), silicosis (SIL; n = 12), cryptogenic organizing pneumonia (COP; n = 5), drug-induced pulmonary fibrosis (DIPF; n = 10), pulmonary Langerhans cells histiocytosis (PLH; 12), scleroderma (SCL; n = 13) patients, and from healthy volunteers (HV; n = 36). Mean values are indicated by horizontal bars; significant differences between the groups are as follows: *P < 0.05, **P < 0.01, and ***P < 0.001.