PPARG and neuroblastoma: Previously, repeated dosing of 100 nM PIO in human neuroblastoma cells has been found to upregulate PGC-1α expression and promote mitochondrial biogenesis [56], and PPARγ stimulation using 100 nM to 1 μM PIO was also reported to promote neurite outgrowth [57], although mitochondrial integrity was found to be compromised at more than 20 μM [48].