VSNL1 and Parkinson disease: Previously, many CSF biomarkers, such as total α-synuclein [9–13], phosphorylated α-synuclein, oligomeric α-synuclein [10], DJ-1 [11], neurofilament light chain protein [12], visinin-like protein-1 (VILIP-1) [13], and cocaine and amphetamine regulated transcript (CART) [14] have been reported to be useful for diagnosing preclinical and clinical PD and DLB, and distinguishing DLB from AD.