QPCT and thyroid cancer: QPCT is highly expressed in melanoma32 and thyroid cancer.33–35 In addition, QPCT can promote the migration and proliferation of thyroid cancer cells14; it can also promote the proliferation and angiogenesis of renal cancer cells, inhibit apoptosis, and play a role in chemoresistance development.18,19 However, the biological function of QPCT in breast cancer cells has not been fully explored.