NEFL and neurodegenerative disease: Previous studies have shown that NfL expression was associated with dementia (Rosengren et al., 1999; de Jong et al., 2007; Howell et al., 2017; Zhao et al., 2019), small vessel disease (Gattringer et al., 2017), and other neurodegenerative diseases (Ge et al., 2018; Khalil et al., 2018; Bridel et al., 2019; Gagliardi et al., 2019; Gao et al., 2020).