PURPOSE OF REVIEW: Focal segmental glomerulosclerosis is a significant and growing cause of chronic kidney disease and nephrotic syndrome in adults and children. RECENT FINDINGS: The last year has seen continued progress in understanding podocyte biology, mechanisms of podocyte dysfunction, and its contribution to proteinuria and focal segmental glomerulosclerosis. SUMMARY: A number of studies have helped to elucidate the mechanisms of slit-diaphragm-mediated signaling to the podocyte cytoskeleton. Advances in treatment continue to lag behind advances in understanding focal segmental glomerulosclerosis disease biology.