Fifty children with asthma (9 to 18 years old, average 13.3 years) and 33 healthy children (average 13.5 years) were assessed for eosinophil cationic protein (ECP) and stimulated interleukin-4 (IL-4) production as asthma-relevant inflammatory markers at baseline and at follow-up an average of 208 days later. This evidence concerns the gene IL4 and asthma.