MGI:3790457 deletion, Chr 4, Anton Berns 1 Cdkn2a/Cdkn2b<tm1Nki> Del(4Cdkn2a-Cdkn2b)1Brn Cdkn2a/Cdkn2b<tm1Brn> http://identifiers.org/mgd/MGI:3790457 Null/knockout