Independent of antigen presentation, B cells interact with activated CD8+ cytotoxic T cells, in part through engagement of CD27 (expressed by B cells) and CD70 (expressed by T cells), to promote survival and proliferation of the T-cell subset.121 CD8+ T cells in blood from patients with uveitis express markers of cytotoxicity, including CD107a, and demonstrate enhanced target cell lysis (Hirani S, et al. IOVS 2013;54: ARVO E-Abstract 2026). This evidence concerns the gene CD8A and uveitis.