Forcing the third dimension.

One goal of biomedical research is to reliably construct surrogate tissues for replacement therapy and to promote tissue regeneration. In this issue of Cell, Chun et al. (2006) provide insight into the molecular basis of tissue-specific differentiation. The authors show that remodeling of the extracellular matrix by the matrix metalloproteinase MT1-MMP contributes to the three-dimensional development of white adipose tissue in mice.