For example, lysozyme (LYZ), a polymeric immunoglobulin receptor (PIGR), a prolactin-induced protein (PIP), and cystatin S (CST4), which have all been found to be decreased in DE [51], are observed to be increased in the treatment-naïve glaucoma patients, before decreasing in the topically treated patients. Here, CST4 is linked to glaucoma.