CRISPR/Cas9 technology was used to induce double-strand breaks within introns 45 and 53 and excise exons 46-53, thus deleting the RWD Binding Domain (RWDBD). Immunoblot analysis of homozygous mutant mouse embryonic fibroblasts (MEFs) revealed that the level of protein expression is reduced to 30% relative to that in wild-type MEFs. (J:287528)