COL1A1 and idiopathic pulmonary fibrosis: ECM_BCs(KRT5+/VCAN+, Fig. 6H, yellow arrows) and ECM_FIB(COL1A1+/POSTN+, Fig. 6J, yellow arrows) were found in subepithelial regions around airways in IPF and rarely around airways in control lungs(Fig. 6G–J).