Figure 5 of Inagaki, Mol Vis 2011; 17:598-606.

Figure 5. Hypothetical etiology of corneal perforation in cGVHD patients. CD68+ macrophages engulf and degrade the recipient’s degenerated epithelium as a foreign body, leading to the secretion of a large amount of proinflammatory cytokines, and the subsequent expression of MMP9 on macrophages or the corneal stroma and epithelium.