(e) A histological section through a hair follicle (left, phase-contrast microscopy) stained for the stem-cell marker keratin 15 (K15) to identify the bulge region (dotted box), the stem-cell niche. DNA stain (DAPI) and the phase-contrast microscopy image show full follicle architecture. (f) Upper panels show MBd-accumulating cells in the bulge region (boxed) co-labelled with K15 and MKLP1. Enlargements (lower panels) of the boxed region highlight a cell with four MBds (asterisks). N, nucleus. Scale bar, 5 μm. 