B1-8+/+Jkappa<-> Igh<B1-8f> MGI:2388394 B1-8H targeted mutation 4, University of Cologne Conditional ready|No functional change VNP VHB1-8 VHB1-8f B1-8f Igh<tm4Cgn> http://identifiers.org/mgd/MGI:2388394