CXCL12 and sympathetic ophthalmia: Specifically, Abu El-Asrar et al. cite elevated gelatinase B (matrix metalloproteinase-9) and chemokines monocyte chemotactic protein-1 (CCL2/MCP-1) and stromal cell-derived factor-1 (CXCL12/SDF-1) within cells in granulomas of sympathetic ophthalmia [42].