Consistent with the microarray results, IHC demonstrated that the FGF2 and HGF proteins were generally positively expressed in IPF lungs and weakly or negatively expressed in control lungs, whereas HBEGF, ERBB3, and ANGPT2 were weakly expressed in IPF lungs and positively expressed in control lungs (Figure 9(a)). Here, ERBB3 is linked to idiopathic pulmonary fibrosis.