| Primary Identifier | MGI:1857187 | Allele Type | Targeted |
| Attribute String | Null/knockout | Gene | Ighm |
| Transmission | Germline | Strain of Origin | 129S2/SvPas |
| Is Recombinase | false | Is Wild Type | false |
| molecularNote | A neomycin resistance cassette disrupted one of the membrane exons of the gene encoding immunoglobulin heavy chain of the class mu (IgM). |