Coherently, inhibition of SPHK2 leads to downregulation of mitochondrial-related genes such as proliferator-activated receptor γ coactivator-1α (PGC-1α) and its downstream targets nuclear respiratory factor 1 (NRF-1) and mitochondrial transcription factor A (TFAM) in multiple PD experimental models (Sivasubramanian et al., 2015). The gene discussed is NRF1; the disease is Parkinson disease.