Smith completed
postdoctoral research appointments at
Harvard Medical School from 1979 to 1981 and the Imperial Cancer Research Fund (now Cancer Research UK) from 1981 to 1984. In 1984 he joined the staff of the
National Institute for Medical Research (NIMR), becoming head of the Division of Developmental Biology in 1991 and head of the Genes and Cellular Control Group in 1996. He moved to become director of the
Gurdon Institute in 2001, returning to NIMR in 2009 to become its director. In 2014 he became Deputy CEO of the
Medical Research Council in addition to his role as NIMR Director. He led the Wellcome Science Review in 2019. In 2021 he left Wellcome and became Secretary of the
Zoological Society of London. Smith's research has focused on how cells of the very early vertebrate embryo form the specialised tissues of muscle, skin, blood and bone. and that characteristic genes like
Brachyury are turned on at specific concentrations, thus validating
Lewis Wolpert's Positional Information
French flag model of embryonic pattern formation. In other work he shed light on the molecular basis of gastrulation, and especially the role of non-canonical Wnt signalling. His earlier work demonstrated threshold responses in chick limb development and also showed that the
mitogenic response to
growth factors can be active when attached to the
extracellular matrix. ==Awards and honours==