A more-sensitive method to analyze protein interactions has uncovered a new way that cancer cells may use the cell-surface molecule HER3 to drive tumor progression following treatment with HER1 and HER2 inhibitors. The HER family of receptors has been linked to the development of a wide variety of human cancers. HER1 inhibitors such Iressa and HER2 inhibitors such as Herceptin are commonly used in the clinic for treatment of small cell lung carcinoma and breast cancer. A recent study suggests that HER3 levels can predict reduced breast cancer survival. However, HER3 inhibitors are not currently used in treatment.
