Although corneal grafts can restore vision to damaged and opaque eyes, these grafts, like any other transplanted tissue, may be rejected by the host so that blindness returns. In this issue of Molecular Therapy, Oh et al. report that the infusion of human mesenchymal stromal cells (MSCs) prevents allogeneic corneal rejection in a murine model and—crucially—that these benefits may be mediated by a soluble, MSC-derived anti-inflammatory protein, tumor necrosis factor-α (TNF-α) stimulated gene/protein 6 (TSG-6).1 If similar effects can be produced in humans, injection of the recombinant protein may greatly increase the success and survival of corneal grafts.