FSTL1 and neoplasm: While some of the aforementioned genes have been previously discussed in the context of pterygia, this study identifies several pterygia-specific factors that have not previously been associated with the disease, such as AHNAK, RTN4, TPT1, and FSTL1. AHNAK is involved in epithelial mesenchymal transition in response to Transforming Growth Factor beta thereby promoting tumor metastasis (68).