KYN/TRP ratio correlated significantly with CRP (r = 0.28, p = 0.01) and IL-1β mRNA (r = 0.23, p = 0.03) in schizophrenia patients but not in controls (CRP r = 0.13, p = 0.28; IL-1β mRNA, r = −0.14, p = 0.26, Supplemental Table S13). The gene discussed is IL1B; the disease is schizophrenia.