To provide a method for screening an immunosuppressant, a therapeutic agent of dermatoses or a depilation preventive.

A keratinocyte is cultured in both of the presence and the absence of a material to be tested, and an RNA is extracted from the cultured cells. An mRNA encoding follistatin is detected from the both cultured material, and the material to be tested is selected as a candidate for an immunosuppressant, a therapeutic agent of dermatoses or a depilation preventive when the difference between the amounts of the mRNA encoding the follistatin is present between the presence and the absence of the material to be tested. The method is useful for a rough screening method for selecting a candidate for a medicine.