Due to the presence of loxP-flanked stop sequences, we cross-bred SMA mice with conditional Munc13-1 knock-in and a Nestin-Cre driver line83 to obtain the following genotype: Smn-/-,Hungtg/+,R26Unc13-1tg/+,Cretg/+ (referred thereafter to as Smn KOR26Unc13-1tg/+). Here, NES is linked to proximal spinal muscular atrophy.