Figure 4. Panel depicting the cellular distribution of Hsp90 in pterygia (A-C) and normal conjunctiva (D). Note the considerable staining heterogeneity in different pterygium samples (A-C). A: Epithelial cells in all layers demonstrate strong Hsp90 in this pterygium sample. Arrows indicate Hsp90 positive endothelial cells. Immunostaining is absent in sections incubated with control IgG (insert). B: Epithelial cells with weak to moderate immunostaining patterns are distributed in all epithelial layers. Immunostaining is absent in sections incubated with control IgG (insert). C: Hsp90-positive cells are adjacent to Hsp90-negative cells, showing the staining heterogeneity within this pterygium sample. D: Epithelial cells with weak cytoplasmic immunoreactivity are detected mainly in basal and suprabasal layers in normal conjunctival samples. (Dako Envision Plus Detection System with hematoxylin counterstain, original magnification X400, bar 50 μm).