In contrast to IFN-α, which was undetectable in both plasma and CSF, IFN-γ plasma concentrations were detected in a minority of SZ patients (n = 2/19) and about half of (n = 6/10) AF patients, with a median concentration of 19.43 pg/mL, whereas HD plasma levels were negative. The gene discussed is IFNG; the disease is atrial fibrillation.