Model of Hif-1 controlling neural crest migration. Neural crest, shown as blue cells, delaminates from the neural tube (NT). Prospective neural crest expresses E-cadherin (E-cad; red), just before EMT Hif-1α activates Twist, which in turn represses E-cadherin expression, allowing neural crest EMT. In addition, Hif-1α activates Cxcr4, which is required for chemotaxis toward SDF-1.