C1QA and diabetes mellitus: C1QA may play a role in the development of diabetic nephropathy [17], and NCLN can be upregulated in tubulointerstitial fibrosis, the hallmark of diabetic nephropathy [18], and IDS, a lysosomal enzyme involved in the degradation pathway proteoglycans, has been suggested to be involved in diabetes complications based on the important role of glycosaminoglycans (GAGs) degradation in both nephropathy and retinopathy [19, 20].