For example, in diabetes-induced nonvalue-added retinopathy, aqueous humor can be utilized for pre-clinical prediction, diagnosis, and determination of the disease stage of diabetes-induced retinopathy by metabolism and proteomics through changes in a number of protein molecules, such as interleukin, apolipoprotein A-I, and brain-specific angiogenesis inhibitory factor 1-associated protein 2 (BAIAP 2), without ocular surgery [71, 72]; detectable differential proteins in aqueous humors can be used to infer the pathogenesis and course of diabetic nephropathy [73]. This evidence concerns the gene APOA1 and diabetes mellitus.