Because the trafficking of HMGB1 between the cell nucleus and the cytoplasm and then into the extracellular space is tightly controlled, we immunoblotted for HMGB1 in each of these fractions in the two major cell types present in the anterior cornea, corneal epithelial cells, which are the first corneal cells to encounter the virus in natural infection, and HCF, the latter previously proposed as a primary source of proinflammatory mediators leading to keratitis in EKC [51]. Here, HMGB1 is linked to keratitis.