SLC7A11 and neoplasm: Tumor cells acquire Cys indirectly via peripheral glutamine using System Xc− as a carrier, SLC7A11 is upregulated in one-third of TNBC cells in vivo, and limiting glutamine uptake or inhibiting System Xc− activity increases intracellular ROS levels and slows TNBC metabolism (Bannai and Ishii, 1988; Timmerman et al., 2013).