The RhoA/ROCK signal transduction can stimulate LIMK1, inactivate cofilin, lead to actin waves, axon elongation, and growth cone disorders, and mediate the axonal degeneration of PD and DA loss (Ohashi et al., 2000; Tilve et al., 2015; Takemura et al., 2009; Wang and Townes-Anderson, 2016). The gene discussed is RHOA; the disease is Parkinson disease.