MAPK7 and Parkinson disease: Cavanaugh and colleagues investigated the contributions of ERK5 and ERK1/2 to the survival of the MN9D murine midbrain dopaminergic neuronal cell line under basal conditions and in response to 6-hydroxydopamine (6-OHDA), a neurotoxic synthetic organic compound used to induce lesions in the nigrostriatal dopaminergic system (a model of Parkinson’s disease).