SDC4 and idiopathic pulmonary fibrosis: The syndecan-4 levels also did not differ between IPF and non-IPF patients, in either the stability period (13.69 ± 4.63 ng/mL vs. 14.34 ± 4.62 ng/mL) or the exacerbation period (9.19 ± 3.86 ng/mL vs. 11.53 ± 6.17 ng/mL).