In mice, hair follicle morphogenesis starts late in Picroside-II embryogenesis and occurs from mid gestation until postnatal day 14�C16. After this period of growth, the first hair follicle cycling is initiated with a catagen phase, in which the hair follicle regresses and the lower two-thirds undergoes apoptosis. Subsequently, the regressed follicle enters the resting telogen phase. The first postnatal telogen phase is short and lasts for one to two days. After this period of quiescence, the first postnatal anagen phase begins, approximately at postnatal day 21�C 25. Although key signalling molecules involved in hair regeneration have been identified, much remains to be learned about how signals are regulated. In light of the recently identified mutations in the LMNA gene, and the skin phenotypes arising thereof, there is a pressing need to increase our understanding of lamin A/C and B expression in different cells of the skin and during hair cycling. In general, it is accepted that lamin B is ubiquitously expressed in most cell types, from the first zygotic cell division through adulthood. A-type lamins are primarily detected in differentiated cells, as indicated by the lack of expression throughout most of mouse embryonic development and in various non-differentiated adult cells and embryonic stem cell lines. We studied lamins A/C and B throughout the mouse HF cycle using immunohistochemistry. This is in contrast to previous studies on lamin A/C expression in human skin, where the lamin A and C proteins were predominantly found in the suprabasal cell layers or at similar levels in all layers of the epidermis. Consistent with our results on lamin B expression, Oguchi and co-workers described high expression of lamins B1 and B2 in basal cells, and lower expression in suprabasal cells of human epidermis. However, other reports on lamin B proteins in human epidermis describe either similar expression throughout the different layers or higher expression of lamin B in suprabasal cells. We do not know if these Ginkgolide-C differences actually reflect differences between humans and mice, or if they are due to differences in experimental procedure. It is interesting to note that we found strong expression of the lamin A/C and lamin B proteins in the dermal papilla and the outer root sheath during all stages of the hair cycle, which argues for the importance of lamins in these compartments of the skin.