Subsequent investigations revealed that GLUT3 not only contributes to the transport of gemcitabine in breast cancer cells but also mediates gemcitabine sensitivity in PC; the knockdown of GLUT3 diminished the chemotherapeutic efficacy of gemcitabine, while SIRT7 knockdown enhanced sensitivity, an effect that was abrogated upon GLUT3 knockdown. This evidence concerns the gene SLC2A3 and breast carcinoma.