Fixing the hole

A hollow glandular architecture is associated with many highly organized tissues such as the mammary gland, and apoptosis functions to create this space. Now, the authors of a recent Cell paper have used non-transformed MCF-10A mammary epithelial cells in a three dimensional cell-culture model — a system in which the cells can take on many of the in vivo features of breast epithelium — to show that apoptosis is important in maintaining luminal space and that tumour cells must suppress apoptosis to successfully invade the lumen.