In the present study, the two-sample MR analysis applying a series of large sample GWAS data indicated that the level of circulating IGF-1 may contribute to the inverse risk of asthma, while there was no obvious evidence to testify the relationship between the level of IGF-1 and COPD, lung cancers as well as IPF. The gene discussed is IGF1; the disease is chronic obstructive pulmonary disease.