SLC7A11 and cancer: Therefore, to better understand the breadth of the xCT functional “network”, it will be essential to elucidate: (i) the factors that regulate its expression in various cell types, (ii) the cognate proteins that interact with xCT on cell membrane in response to engagement by exogenous pathogens, (iii) the downstream genes that are controlled by signals initiated by these interactions at the cell surface, and (iv) whether xCT expression in tumors correlates with disease progression and resistance to chemotherapy in cancer-bearing individuals.