PODXL and Henoch-Schoenlein purpura: Using podocalyxin immunofluorescence, Hara et al. demonstrated that podocytes were shed in urine and an elevated number of podocalyxin-positive cells were observed in active and progressive glomerular diseases such as IgA nephropathy, post-infectious glomerulonephritis, and Henoch Schönlein Purpura (HSP) nephritis [27–29].