**Funding**

Our CRISPR/Cas9 studies are supported in part by a grant from the Fondo de Investigaciones Sanitarias (FIS) of the Spanish Ministry of Economy (PI17/01895), a Novartis grant, and by the Junta de Castilla y León Fondos FEDER (SA085U16), and to the Programa Propio de Ayuda a la Investigación of the University of Salamanca.
