Dorsalizing factor. Key developmental protein that dorsalizes early vertebrate embryonic tissues by binding to ventralizing TGF-beta family bone morphogenetic proteins (BMPs) and sequestering them in latent complexes. Interacts with TWSG1 and/or BMP4. Detected at high levels in 7 dpc mouse embryos; its level decreases at later developmental stages and in adult tissues. Cleaved by tolloid proteases; cleavage participates in dorsoventral patterning during early development. Belongs to the chordin family.