Moreover, across the spectrum from healthy controls to iRBD, PD, and DLB, combined actigraphy-derived rest–activity rhythms and molecular measures suggested a graded, progressive disruption of activity profiles and clock-gene expression, with melatonin appearing selectively impaired in DLB compared with both iRBD and PD (Comas et al., 2025). The gene discussed is CLOCK; the disease is Lewy body dementia.