Table S1 Hair cycle staging of Misu 2/2 mice and their control littermates. For each postnatal day (P), mice are grouped by genotype and gender. The total number of mice is indicated with N. Each mouse is classified into specific hair cycle phases based on established morphological guidelines. Anagen I–IIIa is defined as period starting from the onset of mitotic activity in the hair germ (I) to cells show differentiation into all follicular components (IIIa). Anagen IIIb–VI includes the stage of melanocyte activation (IIIb) to a new hair shaft emerges from skin surface (VI). (DOCX) References 1. Fuchs E (2009) The tortoise and the hair: slow-cycling cells in the stem cell race. Cell 137: 811–819. 2. Cotsarelis G (2006) Epithelial stem cells: a folliculocentric view. J Invest Dermatol 126: 1459–1468. 3. Blanpain C, Fuchs E (2009) Epidermal homeostasis: a balancing act of stem cells in the skin. Nat Rev Mol Cell Biol 10: 207–217. 4. 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