FOXP3 and tuberculosis: Several previous studies confirmed that Treg cells play critical roles in the development of TB and their number increases in peripheral blood and disease sites in patient [7–12].Since FoxP3 is the most specific molecular marker for naturally occurring Treg cells, therefore, many studies has been done on FoxP3 gene expression that some of them have shown increased FoxP3 gene expression in patients with TB [27–29].