To test the relationship between the first variant in PPIP5K2 and the etiology of keratoconus, an animal model was used, where there is a decrease in the phosphatase activity and hyperkinase activity of the PPIP5K2 protein, which is associated with abnormal corneal thinning and epithelial histological changes [46]. Here, PPIP5K2 is linked to keratoconus.