In a follow-up study, they used three phenotypically distinct SMA mouse models and again confirmed that SMN-dependent missplicing of Mdm2 and Mdm4, causing p53 nuclear accumulation, is a conserved pathological mechanism, while the inhibition of p53 prevents motor neuron death in severe and moderate SMA mouse models (Buettner et al., 2021). Here, SMN1 is linked to proximal spinal muscular atrophy.