The lack of a decrease in TH-positive fibers observed in the CPu of adult female Rhes KO mice may be related to compensatory mechanisms such as sprouting and branching, as it has been described, for example, in experimental PD models and in PD patients (Bezard et al., 2000; Finkelstein et al., 2000; Lee et al., 2008). Here, RASD2 is linked to Parkinson disease.