These divergent findings may be due to ethnical differences in various populations that is why the studies that were performed in healthy controls showed allele diversities.[34][35][36][37][38] Generally, the single nucleotide polymorphisms in several candidate genes have been linked to relatively increased risk of TB.[28][29][30][39] Although, studies with higher number of cases might lead to more definite and reliable results regarding the relationship between TNF-α gene polymorphism and pulmonary tuberculosis. This evidence concerns the gene TNF and tuberculosis.