The Successful Aging after Elective Surgery Study examined the association of the levels of plasma NfL, total tau, glial fibrillary acid protein, and ubiquitin carboxyl-terminal hydrolase L1 with delirium, delirium severity, and cognitive performance in older adults without dementia who are undergoing major elective surgery (Fong et al., 2020). The gene discussed is NEFL; the disease is delirium.