a, Expression level change in selected proteins after normalization by RPPA analysis. b and c, Western blotting of EGFL6-mediated activation of PI3K/AKT signaling, Tie2 and EGFR signaling. d, RF24 cells treated with Control (PBS) or EGFL6. Extracts were subjected to anti-Tie2 immunoprecipitation (IP) and integrin α5, αV, β1, and β3 detected by immunoblotting. e, Expression level of pTie2 and pAKT in cytosol and membrane fractions with Control (PBS) and EGFL6 treatment. αβ-tubulin was used as internal control of cytosolic fraction; NaK ATPase was used as membrane marker. f, Silencing of Integrin β1 (ITGB1) and Tie2 using specific siRNAs decreases Tie2 and AKT signaling. g–h, Silencing of Integrin β1 (ITGB1) and Tie2 decreases EGFL6-mediated tube formation (g) and migration (h) in endothelial cells. *p<0.05 vs. Control siRNA. In i–k, RGD blocking peptide decreases Tie2/AKT activation (i), tube formation (j) and migration (k). (n=3) *p<0.05 vs. Control. See also Figure S4.