Table 4. Differentially-expressed genes that distinguish severe IPF from control.

Gene Symbol	Description	Fold Change
IL1R2	interleukin 1 receptor, type II	3.43
DEFA3	defensing, alpha 3, neutrophil specific	3.39
OLFM4	olfactomedin 4	3.39
MMP9	matrix metallopeptidase 9 (gelatinase B)	3.32
GRB10	growth factor receptor-bound protein 10	3.25
DEFA4	defensin, alpha 4, corticostatin	3.00
LTF	lactotransferrin	2.97
RAB8A	RAB8A, member RAS oncogene family	2.76
CTSG	cathepsin G	2.64
CAMP	cathelicidin antimicrobial peptide	2.64
CEACAMP8	carcinoembryonic antigen-related cell adhesion (8)	2.53
VSIG4	V-set and immunoglobulin domain containing 4	2.50
PGLYRP1	peptidoglycan recognition protein 1	2.45
FKBP5	FK506 binding protein 5	2.45
LOC151438	hypothetical protein LOC151438	2.43
ECHDC3	enoyl Coenzyme A hydratase domain containing 3	2.34
LOC100130890	similar to hCG2030844	−2.34
PRSS36	protease, serine, 36	−2.37
MCAT	malonyl CoA:ACP acyltransferase (mitochondrial)	−2.42
IGHM	immunoglobulin heavy constant mu	−3.0

^†Significance analysis of microarrays (SAM) of IPF samples when categorized by percent predicted D_LCO ≤35% [N = 15]. Differentially- expressed transcripts with <1% false discovery rate and ≥ 2-fold change in expression are represented. Fold changes are expressed as log₂ ratio. See supplementary tables for a complete list of differentially-expressed genes and corresponding accession numbers.