A novel compound to induce a pluripotent stem cell is provided. A novel anti-malignant-tumor substance is provided. A pluripotent stem cell-inducing agent, including one or more single-stranded or double-stranded polynucleotides selected from the group consisting of: a) a single-stranded or double-stranded polynucleotide containing a sequence of SEQ ID NO:1 or a sequence including deletion, substitution, or addition of 1 to 3 bases in SEQ ID No: 1, b) a single-stranded or double-stranded polynucleotide containing a sequence of SEQ ID NO:2 or a sequence including deletion, substitution, or addition of 1 to 3 bases in SEQ ID No: 2, c) a single-stranded or double-stranded polynucleotide containing a sequence of SEQ ID NO:3 or a sequence including deletion, substitution, or addition of 1 to 3 bases in SEQ ID No: 3, in which the pluripotent stem cell-inducing agent induces a cell to become a pluripotent stem cell is provided.
