Yann Echelard is senior director of embryology and Harry Meade is senior vice-president of research at GTC Biotherapeutics (previously Genzyme Transgenics), Framingham, MA 01701 yann.echelard@GTC-bio.com.
Cloned cattle engineered to carry an artificial chromosome encoding human immunoglobulin genes are a significant leap toward the production of safer and more potent therapeutic antibodies.