The present invention relates to a method for determining the delivery rates and/or efficiency of a siRNA, miRNA or related molecule to target organs or cells, a kit and the use of proteins or lipids involved in the formation of the endolysosomal system for modulating the activity and/or the cell-to-cell transfer of RNA, small RNA, for example miRNA, siRNA and piRNA, mRNA or non-coding RNA.
It finds many applications in particular in methods for identifying the target(s) of miRNA or siRNA therapeutics, in methods for determining the efficiency of a treatment with siRNA and/or miRNA therapeutics, in methods for determining the efficiency of a treatment with siRNA and/or miRNA therapeutics, and in methods for genotyping and/or characterizing the condition of a person, a tumor or a fetus.