The present invention provides an oligopeptidic compound comprising a PCNAinteracting motif, or a nucleic acidmolecule comprising a sequence encoding said oligopeptidic compound, for usein therapy, wherein the PCNA interacting motif isX1X2X3X3'X1'- (SEQ ED NO: 1), wherein X1 and X1'- are independently selectedfrom the group of basic amino acids, X2 is alipophilic amino acid and X3 and X3' are independently selected from the groupof uncharged amino acids； and wherein theoligopeptidic compound is further characterised by at least one of thefollowing: (i) the oligopeptidic compound comprises at leastone signal sequence； (ii) the PCNA interacting motif is [K/R]-F- {LIV]-[LIV]-[K/R] (SEQ ID NO. 27). Particularly the therapymay be the treatment of a disorder or condition where it is desirable toinhibit the growth of cells, for example a hyperproliferativedisorder, or a treatment which involves cytostatic therapy e.g. myeloablation.In certain aspects the compounds of the inventionmay be used as cytostatic agents in their own right. In other aspects of theinvention oligopeptidic copounds comprising such amotif may be used in conjunction with cytostatic agents or with radiotherapy.
