However, despite rescuing the reduction of MN numbers seen in SMA mice, neither the inhibition of p53 signaling nor virus-mediated overexpression of full-length Mdm2 and Mdm4 is able to rescue vGlut1+-synapse loss (Simon et al., 2017; Van Alstyne et al., 2018). Here, TP53 is linked to proximal spinal muscular atrophy.