Giulio Cossu is Professor of Human Stem Cell Biology at University College London. He made seminal contributions to mammalian embryology. He developed cultures of mammalian somites and showed that the neural tube is required to induce skeletal myogenesis, a notion now in textbooks of Developmental Biology. He pioneered the concept of muscle progenitor heterogeneity. Cossu conducted a “first in man” cell therapy phase I/II in children affected by Duchenne Muscular Dystrophy. The ability to couple developmental biology with stem cell clinical work makes his contribution unique in the field of molecular medicine.