Primary glaucomatous eyes had significantly higher levels of tumor necrosis factor alpha (TNF-α) and interleukin 18 (IL-18) when compared to the POH and control eyes, and IL-18 levels were positively correlated with increasing IOP, findings that may indicate inflammation plays a role in the pathogenesis of primary glaucoma in dogs [21]. The gene discussed is TNF; the disease is Primary glaucoma.