For more than 30 years, the majority of researchers has assumed quiescence to be the default state of all cells and so have provided cells in culture with 'growth factors' to stimulate them to proliferate. During this time, many putative growth factors have been identified and ever more complex mechanisms through which they could interact and stimulate cells have been proposed. However, quiescence as the default state does not make evolutionary sense and many sets of data do not support this hypothesis. In The Society of Cells, an alternative explanation for these results is proposed by...