As a proof-of-principle exploration of the VEGF-TSP1 axis in mammalian lung fibrosis, we measured Tsp1 transcripts in the lungs of bleomycin-treated, WT, and VEGF-Tg mice and found a 1.7-fold increase in the relative expression in the VEGF-exposed lungs at the 48-hour time point following bleomycin (P = 0.0011, Figure 6B). This evidence concerns the gene THBS1 and pulmonary fibrosis.