Using CRISPR/Cas9 technology, a P2A-Cre (encoding a viral 2A oligopeptide that mediates ribosomal skipping and a codon-optimized cre gene) and a myc-tag were inserted into the targetted STOP codon of the Prostate Androgen-Regulated Mucin-Like Protein 1 gene (Parm1) on chromosome 5 in embryonic stem cells. Chimeric mice were generated by aggregating ES cells with morula-stage embryos and bred for germline transmission. (J:101977)