The "Centro Nacional de Biotecnologia" (CNB) is a CSIC Research centre with the aim of translating fundamental biological knowledge into tools and strategies applicable to human health, agriculture and environment, including the generation and analysis of genetically modified mice as experimental animal models of human diseases. The CNB animal house (2000 m2/5000 cages/25000 mice) is divided into four areas (SPF, Conventional, Quaranteen and Inoculated/P3) and currently holds 300 different mouse strains (plus 80 mouse strains that have been cryopreserved).CNB scientific facilities include a Transgenic Unit, a Cryopreservation and a Histology Unit, directed by Lluis Montoliu. CNB will host the Spanish node of EMMA (European Mouse Mutant Archive), coordinated by Lluis Montoliu, National coordinator of the SEBBM Group on “Transgenesis in Mammals” and President of the International Society for Transgenic Technologies.