The present invention is intended to provide a novel molecule that inhibits the expression of the periostin gene that is effective in treatment of diseases caused by the expression of periostin except for eye diseases. A drug for a disease caused by the expression of periostin except for an eye disease includes, as an expression inhibitory sequence for the periostin gene, a nucleic acid molecule including a nucleotide that has a base sequence represented by any one of SEQ ID NOs: 1 to 19. The drug for disease according to the present invention can inhibit the expression of the periostin gene. Thus, it can be used for treatment of diseases (except for eye diseases) caused by the expression of the periostin gene, specifically skin diseases, respiratory diseases, gastrointestinal diseases, and the like.
