TLR3 and idiopathic pulmonary fibrosis: When we compared patients with CTD-IP and HRCT features of UIP to IPF patients, we found that TLR-3 mRNA expression was still significantly higher in CTD-UIP than in IPF (mean ± SD, 3.847 ± 3.804 versus 0.007 ± 0.005; P = 0.002).