To address this knowledge gap, we aimed to identify tissue and circulating biomarkers supporting Nintedanib’s target engagement and anti-fibrotic effect in a double-hit bleomycin rat model of lung fibrosis, while leveraging proteomic analysis of key markers involved in VEGF, PDGF, and FGF2 signaling pathways known to be modulated by Nintedanib [16]. Here, VEGFA is linked to pulmonary fibrosis.