Abstract: Disclosed is a method for stably achieving high expression of a foreign gene in mammalian cells using a novel DNA element. More specifically disclosed is a DNA element which enhances the activation of transcription by changing the chromatin structure around a gene locus into which a foreign gene expression unit has been introduced.

Abstract: A method for stably achieving high expression of a foreign gene in mammalian cells using a novel DNA element is disclosed. More specifically, the present application discloses a DNA element which enhances the activation of transcription by changing the chromatin structure around a gene locus into which a foreign gene expression unit has been introduced.

Abstract: It is intended to provide a peptide library. The present invention provides a peptide selected from the following (1) and (2): a peptide selected from the following (i) and (ii): (i) a peptide comprising the amino acid sequence represented by SEQ ID NO: 1 in the Sequence Listing and further comprising amino acid sequences encoded by nucleotide positions 8 to 42 and nucleotide positions 43 to 93 in the nucleotide sequence represented by SEQ ID NO: 14 in the Sequence Listing to flank the amino terminus and the carboxyl terminus, respectively, of the amino acid sequence; and (ii) a peptide comprising an amino acid sequence, derived from the amino acid sequence represented by SEQ ID NO: 1 in the Sequence Listing, in which conservative amino acid substitution, deletion, addition and/or insertion of 1 to 5 (inclusive) amino acids has occurred, wherein said substitution, deletion, addition and/or insertion has occurred at amino acids other than the 1st Xaa to the 12th Xaa counting from the amino terminus.