clearance of foreign intracellular nucleic acids CRISPR-cas system https://github.com/geneontology/go-ontology/issues/10994 GO:0099048 A defense response of that serves to clear host cells of foreign DNA and RNA. It has three distinct stage: acquisition of foreign DNA by integration into CRISPR loci in the host chromosome, CRISPR RNA (crRNA) biogenesis, and target interference. CRISPR stands for Clustered Regularly Interspaced Short Palindromic Repeat, which describes the nature of the loci. biological_process