We tested Arhgap24 and Srgap1, which were known to regulate the members of the Rho family of small GTPases (RhoA, Rac1, and Cdc42) in podocytes; Arhgap24 mutations can cause focal segmental glomerulosclerosis (FSGS),35 and Srgap1 is important for podocyte foot process maintance.36 This evidence concerns the gene CDC42 and focal segmental glomerulosclerosis.