PPT1 and neuroblastoma: When compared to the empty vector control line, the staining of neuroblastoma KO with MitoTracker Red CMXRos dye and anti-VDAC1 monoclonal antibody (two mitochondrial markers) revealed a fragmented mitochondrial network with an altered distribution around the nuclei (Fig. 3a), as previously observed in primary cells from cases with CLN1 disease13.