20C, a bibenzyl compound isolated from Gastrodia elata (a commonly used traditional Chinese medicine for therapeutic applications, like epilepsy and vertigo treatment), protects PC12 neurons from rotenone-induced lesions mimicking PD in vitro by normalizing (increasing) HMOX1 and NQO1 mRNA and the protein expression level, and by reverting ROS accumulation, cytochrome c release, and apoptosis via NRF2 signaling [47]. This evidence concerns the gene HMOX1 and Parkinson disease.