Interestingly, we observed reduced KPNB1 protein levels in neuronal tissue of two different MJD transgenic mouse models and reduction of both KPNB1 and CLPP protein levels in iPSCs derived from MJD patients, which provides evidence for a pathological dysregulation of KPNB1 and CLPP in MJD. This evidence concerns the gene CLPP and Spinocerebellar ataxia type 3.