Tumour cells that lead the charge in invasive breast cancer express two genes that are required for invasion, and are distinct from cells that make up the bulk of tumours.

Andrew Ewald at Johns Hopkins University in Baltimore, Maryland, and his colleagues studied mouse and human tumour 'organoids', which consist of hundreds of diverse cancer cells.

They found that cells on the leading edge of the organoids' invasive strands express two genes, K14 and p63. These are normally turned on only in cells that lie at the outer edges of epithelial tissue, which lines cavities and surfaces.

Blocking the expression of K14 or p63 in organoids disrupted invasion, suggesting that these and certain other genes in epithelial tissue could be targets for therapies that stop tumours spreading.

Cell http://doi.org/qhc (2013)