Selective Expression of Calcium-Binding Proteins S100A8 and S100A9 at Distinct Sites of Hair Follicles

The study investigated the expression of calcium-binding proteins S100A8 and S100A9 in human hair follicles and found that these proteins were abundantly expressed in the medulla of the hair shaft, particularly during the anagen phase of hair growth. This suggested their role in the terminal differentiation of hair follicle cells. The expression patterns of S100A8 and S100A9 were distinct from other keratinocyte markers like K14, indicating a specific function in hair follicle biology rather than in regular interfollicular epidermis. The study highlighted the potential regulatory roles of these proteins in hair shaft formation and suggested further research to understand their functional relevance.