Recent functional studies in mouse further illustrate the importance of the epithelial–mesenchymal interaction between the ureteric bud epithelium and the metanephric mesenchyme in kidney formation. Genetic ablation of Gdf11, Six1, Slit2/Robo2 reveal a role of these genes in regulating the outgrowth of a single ureteric bud from the Wolffian duct. Studies of Wnt11 and Fras1/Grip1, all expressed in the ureteric bud, show a role for these genes in regulating events in the adjacent metanephric mesenchyme. Furthermore, various approaches were used to address the function of Pod1, Pbx1, the Notch pathway and Brn1 in nephron formation.