When compared to IPF CDM, KRT5+ BCs cultured on collagen I over-expressed genes encoding growth factors (CTGF, HBEGF), pro-inflammatory chemokines (CXCL1, CXCL2) and integrin subunits such as ITGA3. Taken together, these data indicate that the ECM microenvironment plays a critical role in determining gene expression changes in pathways relevant to tissue remodelling and fibrosis. The gene discussed is CXCL2; the disease is idiopathic pulmonary fibrosis.