 Bound to the 5 ' <unk> region of messenger RNA ( mRNA ) , Morpholinos can interfere with progression of the ribosomal initiation complex from the 5 ' cap to the start codon . This prevents translation of the coding region of the targeted transcript ( called " knocking down " gene expression ) . This is useful experimentally when an investigator wishes to know the function of a particular protein ; Morpholinos provide a convenient means of knocking down expression of the protein and learning how that knockdown changes the cells or organism . Some Morpholinos knock down expression so effectively that , after degradation of preexisting proteins , the targeted proteins become undetectable by Western blot ( e.g. , figure 1 in : ) . 
