To determine whether post-exposure to PF543, a SPHK1 specific inhibitor can reduce lung fibrosis in vivo, we used two murine pulmonary fibrosis models resulting from exposure to either bleomycin (spontaneously resolves) or amphibole crocidolite asbestos (nonresolving) [34]. The gene discussed is SPHK1; the disease is pulmonary fibrosis.