The development of several types of skin appendages is guided by prenatal ectodysplasin signaling. In this issue, Cui et al. report on the dose and duration of ectodysplasin signaling required for the maintenance and morphogenesis of different types of appendages. They report that achievement of an intimate arrangement between epithelial and mesenchymal cell populations correlates with the acquisition of autonomy from ectodysplasin stimulation.