Abstract: Provided is a cassette for deleting a target gene comprising (a) a promoter-specific homologous region having a sequence identity to a portion of a promoter region of the target gene, wherein the degree of sequence identity is sufficient to drive homologous recombination therebetween, (b) a marker gene operably linked to the promoter-specific homologous region, and (c) a gene-specific homologous region adjacent to 3?-end of the marker gene and having a sequence identity to at least a portion of the target gene, wherein the degree of sequence identity is sufficient to drive homologous recombination therebetween.