Significantly increased expression of IL-1RA, IL-6, IL-8, GRO, G-CSF was observed in the vitreous from patients with culture negative but presumed infectious endophthalmitis compared to the non-infectious controls and a cluster analysis of these cytokines distinguished the patients with endophthalmitis from the control group, thus providing us a five-biomarker signature. The gene discussed is CSF3; the disease is endophthalmitis.