The functional unit of the human kidney is a blood filtering nephron. The nephron arises from a cluster of cells called the renal vesicle (gold) formed by streams (red) of stem cell-like nephron progenitor cells (green) within the nephrogenic niche. Each renal vesicle produces a single nephron. In this, the renal vesicle transitions through an S-shaped intermediate (green-orange-pink structures) eventually forming the expansive tubular network of the functional nephron (white). (Video courtesy of Nils Lindstorm, Andy McMahon, Seth Ruffins and the Microscopy Core Facility at the Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research at the Keck School of Medicine of USC)