The allele was created using CRISPR/cas9 endonuclease-mediated genome editing to target the stop codon of the transmembrane protein 119 locus (Tmem119) on chromosome 5. The cas9-RNP complex and a 2A-CreERT2 dsDNA (encoding a viral 2A oligopeptide that mediates ribosomal skipping and the CreER fusion gene with ~1.5 kbp homology arms were injected into the pronucleus of C57BL/6NTac mouse embryos. Founders were bred to C57BL/6J mice for germline transmission. (J:280123)