Epithelial cells in remodeled areas of lung tissue from patients with UIP express p16 and p21, markers of cell senescence [42], and these senescent cells secrete pro-inflammatory molecules, including interleukin (IL)-1a, IL-1b, IL-6, and IL-10, as well as TGF-β [42]. This evidence concerns the gene TGFB1 and idiopathic pulmonary fibrosis.