Mouse substrains derived from pedigreed stocks from The Jackson Laboratory are provided to end users solely to support internal research use. Animals supplied by the Animal Resources Centre are not to be used for breeding unless approved by the CEO. Where breeding is permitted an ‘Institution Breeding contract’ may be required. The purpose of restricting breeding is to ensure that the genetic characteristics of the strain are maintained. Progeny of these substrains should not be transferred or sold to other third parties for any purpose.