IL1B and asthma: No association was found between IL-1β -511C/T polymorphism and asthma risk (dominant model: OR = 1.11, 95% CI: 0.99–1.25, P = 0.07, PHeterogeneity = 0.06; recessive model: OR = 1.04, 95% CI: 0.91–1.20, P = 0.55, PHeterogeneity = 0.11).