This is supported by a report examining the expression of TRAIL and its receptors in normal and IPF lungs, where both TRAIL protein and its receptors were expressed by epithelial cells adjacent to fibroblastic foci and, to a lesser extent, in fibroblastic foci; however, unlike hyperplastic epithelial cells, fibroblasts present in the foci were devoid of apoptosis inducing p53 protein [55]. The gene discussed is TP53; the disease is idiopathic pulmonary fibrosis.