The great challenges in Developmental Biology are to understand how the form and shape of embryos emerge and to work out details of developmental pathways. A pivotal mechanism for generating spatial organisation during embryo development is through cell-cell interactions, in which one set of cells tells another set what to do.

Developmental Genetics has been very powerful in identifying important genes that control developmental pathways but embryos are built of cells and we are still relatively ignorant about the cellular basis of development.

Understanding normal development casts light on how developmental abnormalities arise and many of the same molecules that control embryonic development are also implicated in cancer.