We assessed the impact of Endothelial Focal Adhesion kinase (ECFAK) knockout, using primary lung endothelial cells isolated (at P10-P14) from a FAK flox/flox mice crossed with mice expressing a tamoxifen-inducible Cre(iCreERT2) that is driven by endothelial cell (EC)-selective platelet-derived growth factor subunit B (Pdgfb) promoter (Pdgfb-iCreERT2) (Tavora et al., 2010). To induce EC restricted FAK deletion, we injected 4-hydroxytamoxifen (4-OHT) from postnatal day 1 (P1) to P2. Molecular signaling events modulated by ECFAK loss, with or without ex vivo VEGF stimulation, were then examined by phospho and total quantitative proteomics analysis using 6plex isobaric tandem mass tagging multiplexing (TMT). In total, three experiments were performed (a an initial pilot experiment not included in this study, followed by two main biological replicates included - i.e. experiments 2, and 3). The following 4 TMT channels were utilised in each experiment: TMT-126: WT-mock(PBS) stimulated TMT-127: WT-Vegf stimulated TMT128: FAK KO-mock (PBS)stimulated TMT 129:FAK KO-Vegf stimulated