SOX9 and Hand-foot syndrome: Furthermore, given the comparable immunostaining of HFSC markers CD34, Sox9, NFATc1, and K15 (Figure S1B‐D) as well as the lack of TUNEL staining in control and Hes1eKO HFs (Figure S1E), we demonstrated that neither loss of HFSCs nor increased cell death in the HG accounted for the delayed anagen entry in Hes1eKO HFs.