Primary human umbilical vein endothelial cells (HUVECs) were cultured at 37 °C and 5% CO2 in a humidified incubator in the endothelial cell growth basal medium-2 supplemented with 2% fetal bovine serum and growth supplements (Lonza, Basel, Switzerland). HUVEC passages between 4 and 8 were used in the present study. Murine brain endothelial cells were isolated from 8- to 10-week-old Gab2−/− mice and WT (wild type) littermate controls using the procedure described in our recent publication.34 (link)