The Nephrotic Syndrome Study Network (NEPTUNE) is a multi-disciplinary, multi-center longitudinal observational study. The main purpose of this study is to find markers for progression of Nephrotic Syndrome. We are particularly interested in the diseases called Focal and Segmental Glomerulosclerosis (FSGS), Minimal Change Disease (MCD), and Membranous Nephropathy (MN), which …