GRM1 and Arthritis: Of the 5 drugs targeting SLC7A11, riluzole, a noncompetitive metabotropic glutamate receptor 1 (mGluR1) antagonist, and sulfasalazine, a cystine/glutamate antiporter system xc-inhibitor used to treat inflammatory bowel disease and arthritis, have antitumor properties [48,49,50].