A complex I accessory subunit known as GRIM19 (Genes associated with Retinoid–IFN-induced Mortality-19), or NDUFA13, showed an increase in expression in cerebellar and occipital white matter in MSA as well as in the PD occipital matter (Fig. 2c; p = 0.0256, 0.0418, 0.001 respectively). Here, NDUFA13 is linked to multiple system atrophy.