A simple observation often can lead to unexpected opportunities. Such was the case for Vion Pharmaceuticals Inc. researchers, who presented preclinical results last week on a new cancer therapy involving Salmonella bacteria at the American Association for Cancer Research meeting in San Diego.

VION scientists made a connection between some common properties of metastatic tumor cells and the normal activity of some lymphocytes, and guessed that tumor cells might engulf bacteria in a fashion similar to macrophages - making bacteria potentially useful as delivery vehicles to tumors.