Glutamic acid codon 153 (GAA) was targeted for change to an aspartic acid codon (GAC)(p.E153D) with an sgRNA (targeting GACTTTTCTTCTTCAATCCTTGG) and an ssODN template using CRISPR/Cas9 technology. This mutation disrupts the BS2 binding site that normally allows binding of protein phosphatase 2A through the PP2A B56 regulatory subunits. (J:307293)