A second study focusing on the effect of co-culturing healthy or psoriatic KC with healthy T lymphocytes found that psoriatic KC enhanced T lymphocyte survival when co-cultured, with an overproduction of proinflammatory cytokines including TNF-α, IL-6, IL-8, GM-CSF, MCP-1 and IL-10. This evidence concerns the gene CCL2 and keratoconus.