 It has been suggested that CRISPR interference systems in prokaryotes are analogous to eukaryotic RNA interference systems, although none of the protein components are orthologous.RNA interference is a vital part of the immune response to viruses and other foreign genetic material, especially in plants where it may also prevent the self-propagation of transposons.Plants such as "Arabidopsis thaliana" express multiple dicer homologs that are specialized to react differently when the plant is exposed to different viruses.