The underlying mechanisms whereby cells sense and respond to external stimuli are not well understood, but for some time it has been known that the extracellular matrix has an influence on the behavior of cells. For example, changing the flexibility and/or adhesiveness of the matrix can change the shape of cells, and determine whether or not they continue to divide or begin to differentiate. Recently, in a series of elegant experiments, a group of cell biologists in Boston have demonstrated the presence of an interconnected molecular network pervading the entire living cell, extending from its outer surroundings into the genes in its nucleus.