CD44 and focal segmental glomerulosclerosis: So far, several disease-specific biomarkers have been identified, such as CD44 in membranous nephropathy, dipeptidase 1 (DPEP1) and apolipoproteins in focal glomerulosclerosis (FSGS), and the laminin G-like 3 (LG3) fragments of endorepellin in IgA nephropathy [110,111].