Objective  To study the expression of lymphoid enhancer factor-1 (LEF-1) in the growth cycle of rat whisker hair follicle and explore its role in the process.   Methods  Cheek skin samples of SD rats at different ages were collected

fixed and sectioned. LEF-1 expression at different periods was detected by immunohistochemistry.   Results  In anagen

LEF-1 was expressed in the nucleus of bulb and outer root sheath (ORS) of the hair follicle cells

and then with further growth

this nuclear expression pattern gradually converted into cytoplasm expression. In catagen

the staining of LEF-1 became weaken obviously

and disappeared in ORS. In telogen

the expression of LEF-1 appeared in the lateral of bulge again and was strong in IRS.   Conclusion  LEF-1 may regulate the differentiation of hair shaft and inter root sheath (IRS)

and play an important role in the cycle of hair follicle.