The anti-neural role of BMP signaling is a consequence of its ancestral function in dorsoventral patterning. - Knabl, Paul; Ordoñez, June F.; Montenegro Cabrera, Juan Daniel; Abed-Navandi, Daniel; Halbauer, Roland; Link, Oliver; Wollesen, Tim; Genikhovich, Grigory (PLoS Biology, 2026)