The present invention relates to a single-stranded oligonucleotide, wherein all nucleosides of the oligonucleotide are 2’ O alkyl ribose ribonucleosides, for use in the treatment of the human or animal body, wherein said oligonucleotide is capable of making a change in the sequence of a target RNA molecule present in a living cell of said human or animal body, by providing the oligonucleotide to the living cell under conditions allowing uptake by the living cell of said oligonucleotide, wherein said oligonucleotide comprises a sequence that is at least partially complementary to the target RNA molecule, such that hybridization of the oligonucleotide to the target RNA, or a precursor thereof, or a template therefor, takes place in said living cell, allowing biochemical machinery present in said living cell to copy a difference in sequence of the oligonucleotide relative to the target RNA molecule onto the RNA molecule, either directly or via a precursor thereof or a template there for, so as to bring about the change in said target RNA.
