GLI1 and hydrops fetalis: Another population of Gli1+ cells, localized to the lower portion of bulge/HG, respond to DP/HG‐releasing Shh and contribute to immediate HF growth in anagen.39Hes1 expression in the lower bulge/HG during anagen initiation suggests a crosstalk between Notch and Hedgehog signaling pathways in this compartment (Figure 7B).