TNF and age-related macular degeneration: Also, for simplicity only Tnf mRNA expression is depicted, but the gene-induction pattern was similar for Il12a, Nos2, and Il6. We first examined cooperation between CEP and inflammatory cytokines because this mimics the inflammatory microenvironment of certain disease states that are characterized by chronic low-grade inflammation and the absence of overt pathogens (e.g., atherosclerosis, AMD, cancer).