Mice used for this study included wild type female and male C57BL/6J, male Myh11-CreERT2; Tgfbr2fl/fl; mT/mG or male Cdh5-CreERT2; Tgfbr1fl/fl; Tgfbr2fl/fl; mT/mG. C57BL/6J were purchased from The Jackson Laboratory (Bar Harbor, ME). Myh11-CreERT2; Tgfbr2fl/fl; mT/mG and Cdh5-CreERT2; Tgfbr1fl/fl; Tgfbr2fl/fl; mT/mG were generated as previously described.22 (link),23 (link) The bacterial artificial chromosome containing Myh11-CreERT2 inserts on the Y chromosome and female mice do not express the construct. Based on prior studies, female mice have similar fistula dilation and wall thickening as male mice during days 0-21 in this aorta-caval fistula model despite different AVF inflow shear stress.24 (link)