Previous studies have shown greater expression levels of cytokines such as IL-7, IL-8, IL-10, IFN-γ, G-CSF, interferon-inducible protein 10 (IP-10) and IL-1α in the plasma of patients with cytomegalovirus retinitis (CMVR) than in those of patients with ocular syphilis, but in aqueous humour, the levels of IL-1α, IP-10 and GM-CSF were greater (63). Here, IL1A is linked to cytomegalovirus retinitis.