RhoA/ROCK signaling in microglia is increasingly seen as a major contributor to the progression of neurodegenerative disorders [5], with RIs reducing microglial activation in animal models of amyotrophic lateral sclerosis (ALS) [25], Parkinson’s disease (PD) [26,27,28], and Alzheimer’s disease (AD) [29]. Here, RHOA is linked to Parkinson disease.