The mouse line was generated by homologous recombination using the CRISPR/Cas9 technology. A complementary DNA encoding Cre recombinase fused with 2 rox sequences flanking a mutant form of the ESR hormone-binding domain (ERT2) was inserted into the translational start codon ATG of the Nrg1 gene and followed by a polyadenylation sequences. (J:278094)