TAB2 is important for TNF-independent TAK1 regulation of embryonic angiogenesis. (A-B) Whole-mount PECAM-1 staining of TAB2 control (Tab2^flox/flox) and TAB2^ecko (Tie2-Cre Tab2^flox/flox) embryos and yolk sacs at E12.5. Photos show representative specimens from 4 embryos. Arrows indicate truncated vessels. Vessel lengths and branch points were determined in 3 randomly chosen areas from 3 different yolk sacs (graphs). Data are shown as means ± SD (n = 3). Scale bar indicates 200 μm in embryos, 80 μm in yolk sacs. ***P < .001; *P < .05.