Recently, measurement of neurofilament light (NfL) concentration using an ultrasensitive immunoassay on the Single molecule array (Simoa) platform has been demonstrated to be feasible and reliable, both in sporadic Alzheimer’s disease (AD) [6] and ADAD [7], as well as in other neurodegenerative or neuroinflammatory diseases such as frontotemporal dementia [8], progressive supranuclear palsy [9], Huntington’s disease [10], and multiple sclerosis [11]. Here, NEFL is linked to progressive supranuclear palsy.