The authors have established direct correlations between the Crohn's disease activity index and blood content of TNF-α (r = 0.84, p < 0.013), INF-γ (r = 0.61, p < 0.028); between TNF-α and INF-γ content (r = 0.67, p < 0.023), IL-1α (r = 0.49, p < 0.042), IL-6 (r = 0.40, p < 0.045), and IL-8 (r = 0.51, p < 0.033); INF-γ and IL-1α (r = 0.53, p < 0.040), IL-6 (r = 0.37, p < 0.039), IL-8 (r = 0.44, p < 0.040). The gene discussed is IL1A; the disease is Crohn disease.