IL1B and asthma: Table 3 listed the main results of this meta-analysis. Overall, no significantly elevated asthma risk was associated with IL-1β -511C/T when all studies were pooled into the meta-analysis (show in the Table 3). In the subgroup analyses by mean of age and source of controls (population-based and hospital-based), no significant associations were found for all genetic models. The individual risk estimates were calculated and presented as forest plots (Figure 2).