The aim of the invention is to effectively inhibit virus-, bacteria-, or parasite-infected cells and tumor cells in a targeted manner, even in the case of mutations. According to the invention, biologically active molecules are administered, said biologically active molecules including at least one protease inhibitor for at least one specific target protease of the virus-, bacteria-, or parasite-infected cells and/or tumor cells and at least one peptide-inhibited siRNA, PNA or RNA, the peptide bond of which is broken by the at least one target protease for the purpose of activating the peptide-inhibited siRNA, PNA or RNA. The molecules are used, for example, to influence the gene expression of diseased and infected organs or cells.
