H19 and Parkinson disease: Following injection of lentiviral oe-H19 and lentiviral agomir-NC or lentiviral oe-H19 and lentiviral agomir-miR-301b-3p in 6-OHDA-induced PD mice, the number of TH-immunoreactive neurons in the substantia nigra increased after overexpression of H19, but declined with overexpression of miR-301b-3p (Figure 7A).