NFE2L2 and Parkinson disease: Second, among the NRF2 target gens involved in the anti-oxidant pathways, the expression of heme oxyganase 1 (gene symbol, HMOX1; protein, HO-1; involved in heme catabolism and ROS detoxification) was increased in PD SN and globus pallidus interna-GPi (Fig. 2C, GSE7621; GSE20146).