Z/Norrin MGI:4412094 Conditional ready|No functional change Ubb<tm2Nat> Igs1<tm2(CAG-Bgeo,-Ndp,-EGFP)Nat> http://identifiers.org/mgd/MGI:4412094 targeted mutation 2, Jeremy Nathans Iis1<tm2(CAG-Bgeo,-Ndp,-EGFP)Nat>