ETV6-NTRK3—Trk-ing the primary event in human secretory breast cancer

In this issue of Cancer Cell, Tognon et al. (2002) propose a single chromosomal translocation as the cause of a particularly troubling form of breast cancer, secretory carcinoma. They challenge widely held beliefs concerning breast carcinogenesis as well as beliefs concerning the absolute association of specific fusion genes with specific tumor types. Their data highlight the role of Trk signaling in breast cancer and also suggest a target for drug development.