When UNC10217938A is used in the range of 5-25 μM, it can significantly enhance the induction of luciferase in HelaLuc705 cells, and it is more effective and more effective than Retro-1. Compared to a separate splice switch oligonucleotide (SSO), UNC10217938A provids a 60-fold enhancement at 10 μM and 220-fold at 20 μM, in contrast to a 11-fold enhancement for 100 μM Retro-1. UNC10217938A can substantially enhance effects of receptor targeted oligonucleotide conjugates. UNC10217938A can also enhance the effect of uncharged morpholino oligonucleotides and negatively charged oligonucleotides . Exposure of cells to UNC10217938A caused a significant reduction in the colocalization of TAMRA-oligonucleotides with the late ribosomal marker Rab7, but had little effect on the colocalization with the lysosomal marker LAMP-1. UNC10217938A causes partial release of oligonucleotide from late endosomes to the cytosol followed by nuclear accumulation.