IL12A and asthma: In stratified analyses by age (Table 4), it appeared that the allelic frequencies of the A allele at IL-12A rs568408 was significantly higher in the asthma group than the control group among people of less than 37.7 years old (P = 0.0007), but not among people at the age ≥37.7 years old (P = 0.3876).