To strengthen the evidence that decreased ING4 expression may contribute to the progression of fibrosis we sought to correlate ING4 semi-quantitative immunohistochemistry expression levels with pulmonary function parameters including forced vital capacity (FVC), total lung capacity (TLC) and diffuse lung capacity as expressed by KCO (carbon monoxide transfer coefficient), in IPF patients. This evidence concerns the gene ING4 and idiopathic interstitial pneumonia.