IL-22 has been reported to play a role in host defense against bacterial pathogens11. It is involved in host defense at environmental interfaces, such as mucosal surfaces of the airways and gastrointestinal tract. IL-22 can activate STAT3, which is a transcription activator that mediates the expression of a variety of genes in response to various cytokines14. It regulates genes that are involved in antimicrobial defense and cellular differentiation15. IL-22 can restrict the growth of M. tuberculosis in macrophages by enhancing phagolysosomal fusion10. However, the associations between genetic variations in the IL-22 gene and its promoter region and TB susceptibility have never been reported. In this study, we carried out this association study between the IL-22 gene, and found several SNPs in the IL-22 promoter region that influence TB susceptibility.