Studies suggest that IFX and ADA increase the risk of TB compared to ETA.4,12,15 This difference may occur due to the differences in affinity of the receptors of the drugs; IFX has affinity for the TNF 1 receptor and ETA for the TNF 2 receptor.4 The TNF 2 receptor develops a less significant role in defending against TB.4 IFX and ADA reduce gamma interferon production by 65–70%, in contrast to ETA, which causes almost no change in gamma interferon.4 This evidence concerns the gene IFNG and tuberculosis.