To extend our in vitro studies, the efficacy of an orally bioavailable small molecule inhibitor (PXS-S3B, IC500.008 μM and 0.020 μM for LOXL2 and LOXL3, compared with 0.118 μM, 1.130 μM and 1.710 μM for LOXL4, LOX and LOXL1 respectively) was then assessed at LOXL2/LOXL3-selective doses in an experimental animal model of lung fibrosis. This evidence concerns the gene LOXL4 and pulmonary fibrosis.