The present invention relates to a peptide of linear, non-cyclic structure consisting of or comprising 17 to 23 amino acids, wherein the amino acids in positions 1 to 23, counted from the N-terminus, are as follows (1) G, S or lacking; (2) C or lacking; (3) K or R; (4) K or R; (5) Y, W or F; (6) K or R; (7) K or R; (8) F, W or L; (9) K or R; (10) K or L or lacking; (11) W, L or F; (12) K or R; (13) F, Y or C; (14) K or R; (15) G or Q; (16) K or R; (17) F, L or W; (18) F or W; (19) F, L or W; (20) W or F; (21) C or lacking; (22) F or G or lacking (23) G or lacking. Further, the invention relates to a nucleic acid molecule encoding the peptide of the invention, an expression vector comprising the nucleic acid molecule of the invention, a host cell which may be grown in cell culture comprising the vector of the invention, and a method of producing the peptide of the invention comprising culturing the host cell of the invention and collecting the peptide produced. Also, the present invention relates to a pharmaceutical composition comprising the peptide of the invention, the peptide produced by the method of the invention, the nucleic acid molecule of the invention, the expression vector of the invention or the host cell of the invention and a kit comprising the peptide of the invention, the peptide produced by the method of the invention, the nucleic acid molecule of the invention, the expression vector of the invention or the host cell of the invention.