In the prior experiments to determine efficiency of viral infection by stereotaxic injection, we verified coexpression of AAV9-gRNA/RFP and AAV9-Cas9 in the same tyrosine hydroxylase–positive (TH-positive) neurons, which represent dopaminergic neurons, 4 weeks after both viral vectors were coinjected into the monkey SN (Supplemental Figure 5C). Here, TH is linked to viral infectious disease.