Molecular networks altered by the absence of Mmp19 in mouse fibroblasts. The molecular network generated by Ingenuity Pathway Analysis (IPA) software (Ingenuity Systems, www.ingenuity.com) displays interactions between the target genes that were differentially regulated after Mmp19 ablation. Red indicates upregulated, green indicates downregulated, white indicates genes that were not in the data set but form part of this network, and gray indicates genes that were added manually. Solid lines indicates direct relationships between molecules, and dashed lines represent indirect interactions. Results represent data obtained from lung fibroblasts derived from 3 Mmp19−/− and 3 Mmp19+/+ mice.