Rodent and nonhuman primate models of multiple system atrophy (Lee et al., 2019; Marmion et al., 2021) offer experimental tools to investigate cell-specific consequences of caspase-9 activation in neurons and glia and enable studies to test the therapeutic potential of caspase-9 inhibitors as a neuroprotective strategy in MSA. Here, CASP9 is linked to multiple system atrophy.