SLC3A2 and breast carcinoma: Unexpectedly, SLC3A2-KD decreased the total protein levels of SLC7A5 in ER+ breast cancer cells (Fig. 5h and Supplementary Fig. 6o), and conversely, SLC7A5-KD reduced total protein levels of SLC3A2 (Fig. 5i and Supplementary Fig. 6p).