| Primary Identifier | MGI:4456430 | Allele Type | Targeted |
| Attribute String | Modified regulatory region | Gene | Rr155 |
| Transmission | Germline | Strain of Origin | 129P2/OlaHsd |
| Is Recombinase | false | Is Wild Type | false |
| molecularNote | The HS3b transcriptional enhancer, in the 3'RR (Rr152) downstream of the Ighc gene segments, was replaced with a loxP site flanked neomycin resistance gene cassette. Cre-mediated recombination removed the neo cassette. |