TGFB1 and pulmonary fibrosis: Finally, we observed that lung fibrosis was less important in mice with monocyte-restricted deletion of caspase-8 (LysM-Cre; Casp8fl/fl) (Figure 10A–C), which was associated with an increased expression of CD54 on interstitial macrophages (Figure 10D) and a decreased quantity of TGF-beta1 (Transforming growth factor beta 1), as well as several inflammatory cytokines in the broncho–alveolar lavage fluids (Figure 10E).