OLIG2 and fleck corneal dystrophy: To determine in which cell types of FCD lesion there is abnormal upregulation of HMGB1-TLR4 pathway, double staining was performed using anti-TLR4 and anti-HMGB1 antibodies, as well as antibodies specific for neurons (NeuN), astrocytes (GFAP), and oligodendrocytes (Olig2).