PAX2 and focal segmental glomerulosclerosis: The genetic tagging of Pax2+ progenitors of the Bowman capsule of mice allowed to demonstrate that these progenitors differentiate into podocytes in models of focal segmental glomerulosclerosis (FSGS), and their response to injury determines the outcome of glomerular disorders, further substantiating their role as podocyte progenitors [4,12].