Table 1.

Studies utilizing microarray technology to analyze IPF

Investigator	Microarray type	Species/Sample size	Summary/Key findings	Normalization procedure
	Number of genes	Type of tissue		Replications per data point
Zuo et al.22	Oligonucleotide 8.400 genes	5 patients with IPF Lung tissue specimens	Gene expression analysis reveals matrilysin as a key regulator of PF in mice and humans.	Gene expression levels normalized by a scaling factor multiplied to the average of differences of probe pairs (matched-mismatched) / 2 replicates
Kaminski et al.23	Oligonucleotide 6.000 genes	30 mice Lung tissue specimens	Global analysis of gene expression in PF reveals distinct programs regulating lung inflammation and fibrosis.	Mean hybridization intensities of all probe sets on each array were scaled to an arbitrary, fixed level/4 replicates
Katsuma et al. 24	cDNA 4.224 genes	22 mice Lung tissue samples	Molecular monitoring of bleomycin-induced pulmonary fibrosis by cDNA microarray-based gene expression profiling.	Quantified signal intensities were converted by logarithms of base two 4 replicates
Chambers et al. 25	Oligonucleotide 6.000 genes	Human lung fibroblasts	Global expression profiling of fibroblast responses to transforming growth factor-beta1 reveals the induction of ID1.	Gene expression levels normalized by a scaling factor multiplied to the average of differences of probe pairs (matched-mismatched)/ 2 replicates
Liu et al.26	cDNA 10.000 genes	12 rats Lung tissue specimens	FIZZ1 stimulation of myofibroblast differentiation.	Average median ratios Cy3/Cy5 values normalized to 1.0/ 4 replicates

Abbreviations: ID: Inhibitor of Differentiation, IPF: Idiopathic Pulmonary Fibrosis, PF: Pulmonary Fibrosis