FAS and idiopathic pulmonary fibrosis: Knockdown of Fas in IPF cells over-expressing FoxO3a or cav-1 reduced Fas protein levels (Fig. 6E lanes 1 & 2) and significantly decreased IPF fibroblast apoptosis compared to IPF fibroblasts overexpressing FoxO3a or cav-1 but transfected with control siRNA (Fig. 6F upper panel).