Histamine- and serotonin-induced angiogenesis require TR3/Nur77. (A-D) Effects of TR3-antisense vs LacZ, as control, on histamine-, serotonin- and VEGF-A¹⁶⁵–induced ³H thymidine incorporation (n = 4; experiments repeated 3 times), transwell migration (n = 4; experiments repeated 3 times), scratch wound-healing assay migration (n = 20; 3 independent experiments), and tube formation (n = 4; experiments repeated 3 times). Assays were performed as in Figure 1A-D. **P < .01 and ***P < .001, Student t test. (E) Histamine- and serotonin- releasing pellets were harvested 6 days after implantation in Nur77^−/− vs Nur77^+/+ wild-type mice. Angiogenesis with MV (red arrows) developed in Nur77^+/+ but not in Nu77^−/− mice. Data are representative of experiments performed on 8 mice in each group.