COL4A1 and idiopathic pulmonary fibrosis: Of the matrisome genes COL4A1 was down-regulated in IPF compared to ADC and control, POSTN was up-regulated in IPF and ADC compared to control, MMP1 and MMP3 were up-regulated in IPF compared to ADC and control, and because of their differential expression profiles they were chosen for the present research.