Administration of Wnt3a protein coated beads causes premature anagen initiation surrounding telogen hair follicles (A, C), while administration of Dkk1, a Wnt antagonist, prevents normal progression of the physiological anagen spreading wave (E). Control BSA beads can’t induce anagen re-entry (B, D). Red dotted outlines on A, C mark boundaries between anagen and telogen skin. Adopted from Plikus et al., 2011.