Watanuki S, et al. - Authors herein described the centrosome duplication cycle in human epidermis, Bowen’s disease (BD), and squamous cell carcinoma (SCC). They noted that the cell cycle arrest of suprabasal cells was distinct from the G0 arrest of monolayered epithelial cells. Non-proliferative cells with the characteristics of the suprabasal cells of normal epidermis were contained in tumor mass of BD and SCC. It was indicated by the constant ratio of the number of centrobin+ to ODF2+ centrioles that rather than centriole overduplication in clumping cells, multiple centrioles were induced by cell division failure.