Nakamura et al. (2021) demonstrated another role of UCH-L1 in Alzheimer's disease: the DUB can function as an upstream signaling molecule participating in an intracellular cascade involving Cdk5 and leading to the transfer of nitric oxide (NO) to the mitochondrial GTPase Drp1 to form NO-Drp1. The gene discussed is UCHL1; the disease is Alzheimer disease.