Interestingly, thymic medullary fibroblasts in mice produce distinct self-antigens and express lymphotoxin-β receptor (LTβR), which is central for T-cell tolerance.113 LTβR deletion in these fibroblasts resulted in spontaneous loss of immune tolerance in murine models, with autoantibody production observed in multiple organs, associated with T-cell expansion.113 This suggests that fibroblast subsets have sentinel-like abilities which might also be reflective in GCA-vessels. The gene discussed is LTBR; the disease is temporal arteritis.