In pterygium, a benign condition in which wedge-shaped epithelial fibrovascular proliferation of the conjunctiva extends onto the cornea, altered methylation patterns were detected at CpG loci near the genes encoding transglutaminase 2 (TGM2), metalloproteinase 2 (MMP2), and CD24. Hypermethylation at the promoter region of TGM2 led to decreased transcript and protein levels, and hypomethylation of intergenic regions of MMP2 and the promoter region of CD24 led to increased transcript and protein levels. This evidence concerns the gene MMP2 and pterygium.