FYN and Parkinson disease: Of all synaptic proteins, in addition to αSyn (SNCA), also CNTNAP1, encoding contactin-associated protein 1; FYN (FYN proto-oncogene, Src family tyrosine kinase), encoding tyrosine-protein kinase Fyn; and STX1B, encoding syntaxin 1B, were genes previously associated with PD in GWAS.