IDO1 and Stroke: The results preliminarily indicated here that IDO1 rs9657182 T allele was a suggestive predisposing factor for early-onset PSD, which was associated with increased serum IDO1 levels possibly due to the T allele affecting the transcriptional activity of the promoter region of the IDO1 gene, and that patients with acute stroke who carry the rs9657182 T/T genotype had an increased susceptibility to early-onset PSD, and that serum IDO1 levels were an independent risk factor for early-onset PSD, and that serum IDO1 levels in stroke settings were relevant to the TNF-α rs361525 polymorphism.