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The discovery of insulin in 1921 was one of the great medical advances of the twentieth century. Since then, key discoveries have led to a molecular understanding of the insulin-signalling pathway and revealed targets for the treatment of type-2 diabetes.
Self-regulation is one of the most intriguing properties of early embryos. In 1924, Spemann and Mangold carried out the most famous experiment in experimental embryology, which led to the identification of the first self-organizing centre — the Spemann's organizer.
