The potential role of SHH signaling in the regulation of striatal cholinergic IN physiology prompted (Malave et al., 2021) to test whether the acute or chronic co-application of a SHH agonist (SAG or purmorphamine) or antagonist (cyclopamine) during L-DOPA treatment would attenuate or increase, respectively, the appearance of LIDs in mouse and primate PD models. This evidence concerns the gene SHH and Parkinson disease.