These as well as other investigators identified increased expression of cellular FLICE-like inhibitory protein (c-FLIP) as also contributing to the resistance of fibroblasts to apoptosis,15, 37 although this was not consistently observed among fibroblasts in IPF tissue.38 Increased expression of inhibitors of apoptosis such as survivin14, 39 and X-linked inhibitor of apoptosis (XIAP)15 may also have a substantial role in apoptosis resistance. This evidence concerns the gene CFLAR and idiopathic pulmonary fibrosis.